[Event "Spandau Christmas op 6th"]
[Site "Spandau"]
[Date "2023.12.28"]
[Round "3"]
[White "Krefenstein, Sergej"]
[Black "Foerster, Jonas"]
[Result "1/2-1/2"]
[ECO "E12"]
[WhiteElo "2029"]
[BlackElo "2275"]
[PlyCount "62"]
[EventDate "2023.12.27"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "GER"]
[SourceTitle "CB01_2024"]
[SourceDate "2024.01.03"]
[SourceVersion "1"]
[SourceVersionDate "2024.01.03"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. a3 Bb7 5. Nc3 d5 6. cxd5 exd5 7. Bf4 a6 8. e3 Bd6 9. Bg3 Bxg3 10. hxg3 Nbd7 11. Bd3 Qe7 12. Qc2 g6 13. Rc1 c5 14. dxc5 Nxc5 15. 0-0 0-0 16. b4 Ne6 17. Ne2 Rfc8 18. Qb2 Nd7 19. Ned4 Qf6 20. Rxc8+ Rxc8 21. Rc1 Rxc1+ 22. Qxc1 Nxd4 23. exd4 Qd6 24. Qe3 Nf6 25. Ne5 Kg7 26. Qf4 Qe6 27. Nf3 a5 28. bxa5 bxa5 29. Qc7 Qc6 30. Qxa5 Qc1+ 31. Qe1 Qxa3 1/2-1/2

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2023.07.17"]
[Round "3"]
[White "Matthes, Aaron"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "C86"]
[WhiteElo "2209"]
[BlackElo "2057"]
[PlyCount "104"]
[EventDate "2023.07.15"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. Qe2 Be7 6. 0-0 b5 7. Bb3 0-0 8. c3 d6 9. h3 Nb8 10. d4 Nbd7 11. Rd1 exd4 12. cxd4 Bb7 13. e5 Nd5 14. Nc3 N7b6 15. Bc2 f5 16. exf6 Nxf6 17. Ng5 Qd7 18. Qd3 Qc6 19. d5 Qc4 20. Qe3 Kh8 21. Qe6 Bxd5 22. Nxd5 Qxc2 23. Rd2 Qg6 24. Nxb6 cxb6 25. Qxe7 Rae8 26. Qxd6 Qxg5 27. Re2 Qc5 28. Qxc5 bxc5 29. Rxe8 Rxe8 30. Be3 c4 31. Rd1 Re6 32. Bg5 Kg8 33. Kf1 Kf7 34. Bxf6 Kxf6 35. Re1 Rxe1+ 36. Kxe1 Ke5 37. a3 Kd4 38. Kd2 a5 39. g4 g5 40. f3 b4 41. axb4 axb4 42. Ke2 c3 43. b3 Ke5 44. Ke3 h6 45. Kd3 Kf4 46. Ke2 c2 47. Kd2 Kxf3 48. Kxc2 Ke2 49. Kc1 Kd3 50. Kb2 Kd2 51. Kb1 Kc3 52. Ka2 Kc2 1-0

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2022.07.17"]
[Round "9"]
[White "Dathe, Frederick"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "A12"]
[WhiteElo "2094"]
[BlackElo "2090"]
[PlyCount "96"]
[EventDate "2022.07.09"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 209 Extra"]
[Source "ChessBase"]
[SourceDate "2022.09.30"]
[SourceVersion "1"]
[SourceVersionDate "2022.09.30"]
[SourceQuality "1"]

1. c4 Nf6 2. Nf3 c6 3. b3 d5 4. Bb2 Bg4 5. e3 e6 6. Be2 Nbd7 7. 0-0 Bd6 8. Nc3 0-0 9. d4 Qe7 10. Qc2 Rac8 11. h3 Bh5 12. e4 Nxe4 13. Nxe4 dxe4 14. Qxe4 Bg6 15. Qh4 Rfd8 16. Rad1 h6 17. Rfe1 Qxh4 18. Nxh4 Bc2 19. Rc1 Bb4 20. Rf1 Be4 21. Rfd1 Be7 22. Nf3 Bf6 23. Nd2 Bg6 24. Bf3 Nc5 25. Be2 Bd3 26. Bf3 Bf5 27. Be2 Bxd4 28. Bxd4 Rxd4 29. Nf3 Rdd8 30. Kf1 Kf8 31. Rxd8+ Rxd8 32. Rd1 Ke7 33. Rxd8 Kxd8 34. Bd1 Bb1 35. a3 Ke7 36. Ke2 Ne4 37. Ke3 Nc3 38. Be2 Nxe2 39. Kxe2 Be4 40. Ne1 Kd6 41. Ke3 Bb1 42. Nf3 f6 43. g3 e5 44. h4 a5 45. g4 Kc5 46. Nd2 Bc2 47. Ne4+ Bxe4 48. Kxe4 a4 0-1

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2022.07.16"]
[Round "8"]
[White "Krefenstein, Sergej"]
[Black "Maetzkow, Maximilian Paul"]
[Result "0-1"]
[ECO "A46"]
[WhiteElo "2090"]
[BlackElo "2291"]
[PlyCount "78"]
[EventDate "2022.07.09"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 209 Extra"]
[Source "ChessBase"]
[SourceDate "2022.09.30"]
[SourceVersion "1"]
[SourceVersionDate "2022.09.30"]
[SourceQuality "1"]

1. Nf3 Nf6 2. d4 e6 3. g3 b5 4. Bg2 Bb7 5. 0-0 Be7 6. a4 b4 7. c4 0-0 8. Nbd2 c5 9. b3 cxd4 10. Bb2 Na6 11. Nxd4 Bxg2 12. Kxg2 Nc5 13. Qc2 Rc8 14. Rad1 Qc7 15. e4 Qb7 16. f3 d6 17. Rfe1 Nfd7 18. Nf1 a6 19. Ne3 Bd8 20. Ne2 Bg5 21. Nf4 f5 22. exf5 Ne5 23. Rf1 exf5 24. Ned5 Rce8 25. Rfe1 Bxf4 26. gxf4 Ng6 27. Kf2 Qd7 28. Rxe8 Qxe8 29. Rg1 Qd8 30. Rg5 Ne6 31. Rxf5 Qh4+ 32. Kg1 Ngxf4 33. Nxf4 Nxf4 34. Rxf4 Qxf4 35. Qe2 Qg5+ 36. Kf2 Qh5 37. Kg2 Re8 38. Qd2 Re6 39. Bd4 Rg6+ 0-1

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2022.07.15"]
[Round "7"]
[White "Muse, Drazen"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "A06"]
[WhiteElo "2317"]
[BlackElo "2090"]
[PlyCount "33"]
[EventDate "2022.07.09"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 209 Extra"]
[Source "ChessBase"]
[SourceDate "2022.09.30"]
[SourceVersion "1"]
[SourceVersionDate "2022.09.30"]
[SourceQuality "1"]

1. Nf3 Nf6 2. b3 d5 3. Bb2 e6 4. e3 b6 5. g3 Bb7 6. Bg2 Nbd7 7. 0-0 Bd6 8. d3 0-0 9. Nbd2 Qe7 10. a4 a6 11. Re1 e5 12. e4 d4 13. Bxd4 exd4 14. e5 Nxe5 15. Nxe5 Bxg2 16. Ng4 Qd8 17. Kxg2 1/2-1/2

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2022.07.14"]
[Round "6"]
[White "Liebelt, Jannik"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "D00"]
[WhiteElo "2094"]
[BlackElo "2090"]
[PlyCount "41"]
[EventDate "2022.07.09"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 209 Extra"]
[Source "ChessBase"]
[SourceDate "2022.09.30"]
[SourceVersion "1"]
[SourceVersionDate "2022.09.30"]
[SourceQuality "1"]

1. d4 Nf6 2. Bf4 d5 3. e3 c5 4. c3 Nc6 5. Nd2 Qb6 6. Qb3 c4 7. Qc2 Bg4 8. b3 cxb3 9. axb3 e6 10. h3 Bf5 11. Bd3 Bxd3 12. Qxd3 Be7 13. Ngf3 0-0 14. 0-0 Qd8 15. Ne5 Nxe5 16. Bxe5 a6 17. Bxf6 Bxf6 18. b4 Qc7 19. Rfc1 Rfc8 20. Nb3 Be7 21. g3 1/2-1/2

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2022.07.13"]
[Round "5"]
[White "Krefenstein, Sergej"]
[Black "Kauschmann, Herbert"]
[Result "1-0"]
[ECO "B38"]
[WhiteElo "2090"]
[BlackElo "2109"]
[PlyCount "111"]
[EventDate "2022.07.09"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 209 Extra"]
[Source "ChessBase"]
[SourceDate "2022.09.30"]
[SourceVersion "1"]
[SourceVersionDate "2022.09.30"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 c5 3. Nf3 cxd4 4. Nxd4 Nc6 5. Nc3 d6 6. e4 Bd7 7. Be2 g6 8. 0-0 Bg7 9. Be3 0-0 10. Qd2 Nxd4 11. Bxd4 Bc6 12. f3 Nd7 13. Be3 a6 14. Rac1 Rc8 15. b3 Nf6 16. Rfe1 Re8 17. Bf1 Nd7 18. h3 Qa5 19. Rc2 b5 20. cxb5 Bxb5 21. Nxb5 Qxd2 22. Rxd2 axb5 23. Bxb5 Red8 24. Ree2 Nc5 25. Kf2 Bc3 26. Rc2 Bb4 27. Kg3 Kg7 28. Rc4 Ba3 29. Rec2 Rb8 30. Ba4 Bb4 31. Bd4+ f6 32. Bc6 e6 33. Bb2 Rb6 34. Ba4 g5 35. Bc3 Ba3 36. Bd4 Bb4 37. Kf2 Rdb8 38. Bxc5 dxc5 39. Ke2 Rd6 40. Rxc5 Bxc5 41. Rxc5 Rbd8 42. Rc2 f5 43. exf5 exf5 44. Bb5 Rd1 45. a4 Rg1 46. Kf2 Rgd1 47. a5 R8d5 48. Be2 Rb1 49. Ra2 Rxb3 50. Bc4 Rbd3 51. Bxd3 Rxd3 52. a6 Rd8 53. a7 Ra8 54. Ke3 Kf6 55. Kd4 Ke6 56. Kc5 1-0

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2022.07.12"]
[Round "4"]
[White "Matthes, Aaron"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "D10"]
[WhiteElo "2146"]
[BlackElo "2090"]
[PlyCount "43"]
[EventDate "2022.07.09"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 209 Extra"]
[Source "ChessBase"]
[SourceDate "2022.09.30"]
[SourceVersion "1"]
[SourceVersionDate "2022.09.30"]
[SourceQuality "1"]

1. d4 d5 2. c4 c6 3. Nc3 Nf6 4. cxd5 cxd5 5. Bf4 Nc6 6. e3 a6 7. Bd3 Bg4 8. f3 Bd7 9. Nge2 g6 10. 0-0 Bg7 11. a3 b5 12. b4 0-0 13. Qb3 Re8 14. Nxd5 e5 15. dxe5 Nxe5 16. Nxf6+ Qxf6 17. Nd4 Nxd3 18. Qxd3 Rad8 19. Rad1 Be6 20. Rfe1 Bc4 21. Qd2 Rd7 22. Bg3 1/2-1/2

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2022.07.11"]
[Round "3"]
[White "Krefenstein, Sergej"]
[Black "Nguyen, Phuc Nhat"]
[Result "1-0"]
[ECO "D74"]
[WhiteElo "2090"]
[BlackElo "1874"]
[PlyCount "65"]
[EventDate "2022.07.09"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 209 Extra"]
[Source "ChessBase"]
[SourceDate "2022.09.30"]
[SourceVersion "1"]
[SourceVersionDate "2022.09.30"]
[SourceQuality "1"]

1. d4 d5 2. Nf3 Nf6 3. g3 g6 4. Bg2 Bg7 5. c4 0-0 6. 0-0 Nc6 7. cxd5 Nxd5 8. Nc3 Nxc3 9. bxc3 e5 10. Ba3 Re8 11. dxe5 Qxd1 12. Rfxd1 Nxe5 13. Nxe5 Bxe5 14. Rac1 c6 15. f4 Bc7 16. Bd6 Bb6+ 17. Kf1 Bg4 18. Bf3 Bxf3 19. exf3 Re3 20. Be5 Rxf3+ 21. Kg2 Rf2+ 22. Kh3 Re8 23. Rd7 f6 24. Bxf6 Ree2 25. Rcd1 h5 26. Kh4 Rxh2+ 27. Kg5 Rhg2 28. Rg7+ Kf8 29. Rdd7 Rxg3+ 30. Kh6 Re6 31. Rxb7 Bc5 32. Rh7 Ke8 33. Rb8# 1-0

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2022.07.10"]
[Round "2"]
[White "Jaeger, Andre"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "A80"]
[WhiteElo "1870"]
[BlackElo "2090"]
[PlyCount "62"]
[EventDate "2022.07.09"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 209 Extra"]
[Source "ChessBase"]
[SourceDate "2022.09.30"]
[SourceVersion "1"]
[SourceVersionDate "2022.09.30"]
[SourceQuality "1"]

1. d4 f5 2. Bg5 g6 3. Nd2 Bg7 4. e3 Nf6 5. h4 h6 6. Bxf6 Bxf6 7. Nh3 0-0 8. Nf4 Kg7 9. h5 g5 10. Nd5 e6 11. Nxf6 Qxf6 12. c3 d6 13. Qc2 Nc6 14. 0-0-0 Bd7 15. f3 e5 16. Be2 Rae8 17. d5 Ne7 18. e4 fxe4 19. fxe4 Qf2 20. Nf3 Qxg2 21. Rhg1 Qf2 22. Qd3 Kh7 23. Rdf1 Qc5 24. Qd2 Rf4 25. Nxg5+ hxg5 26. Rxg5 Rxf1+ 27. Bxf1 Rg8 28. Rxg8 Nxg8 29. Qg5 Qf2 30. Qg6+ Kh8 31. Bg2 Qf6 0-1

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2022.07.09"]
[Round "1"]
[White "Krefenstein, Sergej"]
[Black "Woinowski, Michael"]
[Result "1-0"]
[ECO "D32"]
[WhiteElo "2090"]
[BlackElo "1742"]
[PlyCount "49"]
[EventDate "2022.07.09"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 209 Extra"]
[Source "ChessBase"]
[SourceDate "2022.09.30"]
[SourceVersion "1"]
[SourceVersionDate "2022.09.30"]
[SourceQuality "1"]

1. d4 d5 2. c4 e6 3. Nc3 c5 4. cxd5 exd5 5. Nf3 Nc6 6. dxc5 d4 7. Na4 b5 8. cxb6 axb6 9. b3 b5 10. Nb2 Nf6 11. g3 Bb4+ 12. Bd2 Ne4 13. Bxb4 Nxb4 14. Bg2 Nc3 15. Qd2 0-0 16. 0-0 Bg4 17. e3 Nbxa2 18. Nxd4 Ne2+ 19. Kh1 Re8 20. Rfe1 Nxd4 21. exd4 Rxe1+ 22. Qxe1 Ra3 23. Qd2 b4 24. Nc4 Nc3 25. Nxa3 1-0

[Event "Berlin Teschner Memorial"]
[Site "Berlin"]
[Date "2022.05.28"]
[Round "5"]
[White "Paulsen, Dirk"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "C00"]
[WhiteElo "2309"]
[BlackElo "2103"]
[PlyCount "135"]
[EventDate "2022.05.26"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "GER"]
[SourceTitle "CBM 208 Extra"]
[Source "ChessBase"]
[SourceDate "2022.07.31"]
[SourceVersion "1"]
[SourceVersionDate "2022.07.31"]
[SourceQuality "1"]

1. e4 e6 2. Nc3 d5 3. d3 Nf6 4. e5 Nfd7 5. Nf3 c5 6. Bf4 Nc6 7. g3 Be7 8. h4 a6 9. Bh3 b5 10. Qe2 b4 11. Nb1 a5 12. Nbd2 Ba6 13. c4 bxc3 14. bxc3 h6 15. h5 Rb8 16. 0-0 0-0 17. c4 Nb6 18. Rfc1 dxc4 19. dxc4 Nd4 20. Qe3 Nxf3+ 21. Qxf3 Qd7 22. Bg2 Rfd8 23. Qg4 Kh8 24. Be4 Qd4 25. Qe2 Bb7 26. Bxb7 Rxb7 27. Nb3 Qd7 28. Nxa5 Ra7 29. Nb3 Qc6 30. Nd2 Ra4 31. Rc2 Rd7 32. Kh2 Rda7 33. Ne4 Ra8 34. f3 Rb4 35. g4 Raa4 36. Rac1 Nd7 37. Qd3 f6 38. Rd1 Rb7 39. exf6 Nxf6 40. Nc3 Rd7 41. Qe2 Rxd1 42. Nxd1 Bd6 43. Bxd6 Qxd6+ 44. Kg2 Qc6 45. Rd2 Ra8 46. Nf2 Kg8 47. Qe3 Re8 48. Qe5 Nd7 49. Qe4 Qc7 50. Nd3 Nf6 51. Qe5 Qa5 52. Re2 Nd7 53. Qd6 Qa7 54. Rxe6 Qxa2+ 55. Nf2 Nf6 56. Rxe8+ Nxe8 57. Qxc5 Qd2 58. Qe7 Nf6 59. c5 Nd5 60. Qe8+ Kh7 61. Qe4+ Kg8 62. Kg3 Ne3 63. Qe8+ Kh7 64. Qg6+ Kg8 65. Qe6+ Kh7 66. Qe4+ Kg8 67. c6 Nf1+ 68. Kg2 1/2-1/2

[Event "Berlin Teschner Memorial"]
[Site "Berlin"]
[Date "2022.05.27"]
[Round "3"]
[White "Krefenstein, Sergej"]
[Black "Klenburg, Mikhail"]
[Result "0-1"]
[ECO "A26"]
[WhiteElo "2103"]
[BlackElo "2346"]
[PlyCount "86"]
[EventDate "2022.05.26"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "GER"]
[SourceTitle "CBM 208 Extra"]
[Source "ChessBase"]
[SourceDate "2022.07.31"]
[SourceVersion "1"]
[SourceVersionDate "2022.07.31"]
[SourceQuality "1"]

1. c4 e5 2. Nc3 d6 3. g3 g6 4. Bg2 Bg7 5. e4 Nc6 6. Nge2 Be6 7. d3 Qd7 8. Nd5 Nd8 9. 0-0 c6 10. Ndc3 Bh3 11. d4 h5 12. dxe5 dxe5 13. Qxd7+ Bxd7 14. f4 h4 15. f5 hxg3 16. Nxg3 Bf8 17. Be3 b6 18. Rad1 Be7 19. a3 Nb7 20. b4 Nd6 21. c5 Nc4 22. Bf2 bxc5 23. b5 cxb5 24. Nd5 Rc8 25. a4 Nb2 26. Rb1 Nxa4 27. fxg6 fxg6 28. Be3 Rh7 29. Rfc1 Nf6 30. Nxe7 Rxe7 31. Nf1 a6 32. Bg5 Rf7 33. Ne3 Be6 34. Bh4 Nh5 35. Nd5 Nf4 36. Nxf4 exf4 37. Rf1 c4 38. Bg5 c3 39. Bxf4 c2 40. Rbc1 b4 41. Be5 b3 42. Rxf7 Bxf7 43. Bf1 Nc3 0-1

[Event "Berlin-ch"]
[Site "Berlin"]
[Date "2022.04.15"]
[Round "1"]
[White "Krefenstein, Sergej"]
[Black "Stern, Rene"]
[Result "0-1"]
[ECO "C54"]
[WhiteElo "2158"]
[BlackElo "2509"]
[PlyCount "108"]
[EventDate "2022.04.15"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 207 Extra"]
[Source "ChessBase"]
[SourceDate "2022.05.31"]
[SourceVersion "1"]
[SourceVersionDate "2022.05.31"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. d3 Bc5 5. 0-0 d6 6. c3 a5 7. Nbd2 0-0 8. Re1 Be6 9. Bb3 h6 10. Nf1 Bxb3 11. Qxb3 Qd7 12. a4 Rfe8 13. Be3 Bxe3 14. Nxe3 b6 15. Rad1 Ne7 16. g3 Ng6 17. Kg2 Rad8 18. h3 Qc8 19. Qc4 Qb7 20. Nd5 Nxd5 21. Qxd5 Qxd5 22. exd5 Nf8 23. d4 f6 24. h4 h5 25. b3 Ng6 26. c4 Ne7 27. dxe5 dxe5 28. Rd2 Nf5 29. Re4 Kf7 30. Rde2 Re7 31. Rd2 Red7 32. Ree2 Rd6 33. Kf1 Re8 34. Re4 Re7 35. Kg2 Ke8 36. Kf1 Kd7 37. Ke2 c6 38. dxc6+ Kxc6 39. Rxd6+ Kxd6 40. Kd2 Kc5 41. Kc3 Kc6 42. Re1 Rd7 43. Kc2 Nd6 44. Re2 Nb7 45. Nd2 Nc5 46. Ne4 Nxe4 47. Rxe4 Kc5 48. Re3 Rd4 49. Kc3 e4 50. Re2 Rd3+ 51. Kc2 f5 52. Rd2 Kb4 53. c5 Rxd2+ 54. Kxd2 bxc5 0-1

[Event "Berlin Lichtenrade op 15th"]
[Site "Berlin"]
[Date "2019.10.20"]
[Round "9"]
[White "Krefenstein, Sergej"]
[Black "Nitsche, Nikolai"]
[Result "1-0"]
[ECO "C06"]
[WhiteElo "2139"]
[BlackElo "1789"]
[PlyCount "53"]
[EventDate "2019.10.12"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 192 Extra"]
[Source "Chessbase"]
[SourceDate "2019.11.06"]
[SourceVersion "1"]
[SourceVersionDate "2019.11.06"]
[SourceQuality "1"]

1. e4 e6 2. d4 d5 3. Nd2 Nf6 4. e5 Nfd7 5. Bd3 c5 6. c3 Nc6 7. Ne2 f6 8. exf6 Qxf6 9. Nf3 Bd6 10. Bg5 Qf7 11. 0-0 e5 12. dxe5 Ndxe5 13. Nxe5 Nxe5 14. Bc2 0-0 15. Ng3 Bd7 16. f4 Ng4 17. Qd3 g6 18. h3 c4 19. Qd2 Bc5+ 20. Kh1 Ne3 21. Rf3 Nxc2 22. Qxc2 Rae8 23. Bh6 d4 24. cxd4 Bxd4 25. Bxf8 Rxf8 26. Rd1 Bc5 27. Rxd7 1-0

[Event "Berlin Lichtenrade op 15th"]
[Site "Berlin"]
[Date "2019.10.19"]
[Round "8"]
[White "Shishkin, Vadim"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "D38"]
[WhiteElo "2428"]
[BlackElo "2139"]
[PlyCount "49"]
[EventDate "2019.10.12"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 192 Extra"]
[Source "Chessbase"]
[SourceDate "2019.11.06"]
[SourceVersion "1"]
[SourceVersionDate "2019.11.06"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Nf3 0-0 5. Bg5 h6 6. Bh4 d5 7. e3 Nbd7 8. cxd5 exd5 9. Bd3 Re8 10. 0-0 c6 11. Qc2 Bd6 12. Rae1 Be7 13. Bg3 Nh5 14. Nxd5 Nxg3 15. Nxe7+ Qxe7 16. hxg3 Nf6 17. Ne5 Be6 18. f4 Rad8 19. f5 Bc8 20. Bc4 Nd5 21. e4 Nb4 22. Qb3 Rf8 23. Bxf7+ Rxf7 24. Nxf7 Rxd4 25. Nxh6+ 1-0

[Event "Berlin Lichtenrade op 15th"]
[Site "Berlin"]
[Date "2019.10.18"]
[Round "7"]
[White "Krefenstein, Sergej"]
[Black "Holinka, Henning"]
[Result "1/2-1/2"]
[ECO "B06"]
[WhiteElo "2139"]
[BlackElo "2101"]
[PlyCount "48"]
[EventDate "2019.10.12"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 192 Extra"]
[Source "Chessbase"]
[SourceDate "2019.11.06"]
[SourceVersion "1"]
[SourceVersionDate "2019.11.06"]
[SourceQuality "1"]

1. e4 g6 2. d4 Bg7 3. Nc3 d6 4. f4 a6 5. Nf3 b5 6. Bd3 Nd7 7. a4 c5 8. axb5 cxd4 9. Nd5 Ngf6 10. Nxf6+ Bxf6 11. bxa6 Qb6 12. Qe2 0-0 13. b4 Qxb4+ 14. Bd2 Qb6 15. e5 dxe5 16. fxe5 Bg7 17. 0-0 Bxa6 18. Rxa6 Rxa6 19. Bxa6 d3+ 20. Qe3 Qxa6 21. cxd3 Rb8 22. d4 Qa2 23. Qg5 f6 24. Qg4 Nf8 1/2-1/2

[Event "Berlin Lichtenrade op 15th"]
[Site "Berlin"]
[Date "2019.10.17"]
[Round "6"]
[White "Krefenstein, Sergej"]
[Black "Fuchs, Dominik"]
[Result "1-0"]
[ECO "C54"]
[WhiteElo "2139"]
[BlackElo "1939"]
[PlyCount "63"]
[EventDate "2019.10.12"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 192 Extra"]
[Source "Chessbase"]
[SourceDate "2019.11.06"]
[SourceVersion "1"]
[SourceVersionDate "2019.11.06"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. c3 Nf6 5. d3 a6 6. Bb3 Ba7 7. Nbd2 0-0 8. h3 d6 9. Nf1 d5 10. Qe2 h6 11. g4 dxe4 12. dxe4 Be6 13. g5 Nh5 14. gxh6 g6 15. Bg5 Qd7 16. Rd1 Qe8 17. h4 Bxb3 18. axb3 f5 19. Ng3 fxe4 20. Qxe4 Nf6 21. Qc4+ Qf7 22. Bxf6 Qxc4 23. h7+ Kxh7 24. bxc4 Rxf6 25. Ng5+ Kg8 26. N3e4 Rff8 27. Rd7 Rae8 28. Rxc7 Re7 29. Rxe7 Nxe7 30. Ke2 Rb8 31. Rd1 Nf5 32. Rd7 1-0

[Event "Berlin Lichtenrade op 15th"]
[Site "Berlin"]
[Date "2019.10.16"]
[Round "5"]
[White "Harutyunyan, Axel"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "E11"]
[WhiteElo "1909"]
[BlackElo "2139"]
[PlyCount "82"]
[EventDate "2019.10.12"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 195 Extra"]
[Source "ChessBase"]
[SourceDate "2020.05.31"]
[SourceVersion "1"]
[SourceVersionDate "2020.05.31"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. g3 Bb4+ 5. Bd2 Be7 6. Bg2 0-0 7. 0-0 b6 8. Qc2 Bb7 9. Nc3 dxc4 10. e4 Nc6 11. Ne2 b5 12. a4 a6 13. Rfd1 Nb4 14. Bxb4 Bxb4 15. Ne5 Qe7 16. Nc3 c6 17. Rac1 Rfd8 18. Qe2 Nd7 19. Ng4 Nb6 20. Ra1 Bxc3 21. bxc3 Nxa4 22. Rxa4 bxa4 23. Ra1 c5 24. Qxc4 cxd4 25. cxd4 a3 26. Ne3 Rac8 27. Qa4 Qd7 28. Qxa3 Qxd4 29. Rd1 Qxd1+ 30. Nxd1 Rxd1+ 31. Bf1 Rcc1 32. Qb4 Rxf1+ 33. Kg2 Rb1 34. Qa4 h6 35. f3 Kh7 36. h4 Rg1+ 37. Kh3 h5 38. Qd7 Rb2 39. g4 hxg4+ 40. fxg4 Bxe4 41. Qxf7 Rb3+ 0-1

[Event "Berlin Lichtenrade op 15th"]
[Site "Berlin"]
[Date "2019.10.15"]
[Round "4"]
[White "Krefenstein, Sergej"]
[Black "Bolk, Matthias"]
[Result "1/2-1/2"]
[ECO "B06"]
[WhiteElo "2139"]
[BlackElo "2087"]
[PlyCount "90"]
[EventDate "2019.10.12"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 195 Extra"]
[Source "ChessBase"]
[SourceDate "2020.05.31"]
[SourceVersion "1"]
[SourceVersionDate "2020.05.31"]
[SourceQuality "1"]

1. e4 g6 2. d4 Bg7 3. Nc3 d6 4. f4 Nc6 5. Be3 Nf6 6. Nf3 Bg4 7. d5 Nb8 8. h3 Bxf3 9. Qxf3 c6 10. Bd3 0-0 11. 0-0 cxd5 12. exd5 Nbd7 13. Rfe1 a6 14. Bf1 Rc8 15. Rad1 Re8 16. Rd2 Qa5 17. a3 Nb6 18. Qf2 Nbd7 19. Bd4 Nh5 20. g4 Bxd4 21. Qxd4 Nhf6 22. Rde2 Qb6 23. Qxb6 Nxb6 24. Rxe7 Rxe7 25. Rxe7 Nbxd5 26. Nxd5 Nxd5 27. Rxb7 Rxc2 28. f5 gxf5 29. gxf5 a5 30. b3 Rc7 31. Rxc7 Nxc7 32. Kf2 Kg7 33. Ke3 Kf6 34. Kd4 Kxf5 35. b4 axb4 36. axb4 Ke6 37. b5 Na8 38. Bc4+ Ke7 39. Bd3 h6 40. Kd5 Kd7 41. Ke4 Nb6 42. Kf5 Ke7 43. Kg4 Nd5 44. Kf5 Nb6 45. Kg4 Kf6 1/2-1/2

[Event "Berlin Lichtenrade op 15th"]
[Site "Berlin"]
[Date "2019.10.14"]
[Round "3"]
[White "Alten, Silvio"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "B18"]
[WhiteElo "1893"]
[BlackElo "2139"]
[PlyCount "118"]
[EventDate "2019.10.12"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 195 Extra"]
[Source "ChessBase"]
[SourceDate "2020.05.31"]
[SourceVersion "1"]
[SourceVersionDate "2020.05.31"]
[SourceQuality "1"]

1. e4 c6 2. d4 d5 3. Nd2 dxe4 4. Nxe4 Bf5 5. Nc5 Nd7 6. Bd3 Bxd3 7. Nxd3 Ngf6 8. Nf3 e6 9. 0-0 Be7 10. Qe2 0-0 11. Re1 Re8 12. a4 c5 13. c3 Rc8 14. h3 Bf8 15. Bg5 h6 16. Bh4 Qc7 17. Bg3 Bd6 18. Bxd6 Qxd6 19. Nde5 cxd4 20. Rad1 Nxe5 21. Nxe5 Qc7 22. Rxd4 Red8 23. Red1 Rd5 24. Rxd5 Nxd5 25. c4 Nf6 26. b4 Rd8 27. Rxd8+ Qxd8 28. Qd3 Qb6 29. Qd2 Ne4 30. Qe1 Qd4 31. Nf3 Qxc4 32. a5 a6 33. Ne5 Qd5 34. Ng4 Qd4 35. Ne3 f5 36. Nc2 Qd3 37. Ne3 Kf7 38. Qd1 Qxd1+ 39. Nxd1 Ke7 40. f3 Nf6 41. Nb2 Nd5 42. Nd3 Kd6 43. g3 Kc6 44. f4 Kb5 45. Nc5 Kxb4 46. Nxb7 Ne7 47. Nd8 Kxa5 48. Nxe6 Kb4 49. Kf2 g6 50. Ke2 Kc4 51. Kd2 a5 52. Kc2 Kd5 53. Nc7+ Ke4 54. Ne6 Kf3 55. g4 fxg4 56. hxg4 Kxg4 57. Kb3 h5 58. Ka4 h4 59. Ng5 Kxf4 0-1

[Event "Berlin Lichtenrade op 15th"]
[Site "Berlin"]
[Date "2019.10.12"]
[Round "1"]
[White "Baumeister, Wolfgang"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "A03"]
[WhiteElo "1756"]
[BlackElo "2139"]
[PlyCount "96"]
[EventDate "2019.10.12"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 195 Extra"]
[Source "ChessBase"]
[SourceDate "2020.05.31"]
[SourceVersion "1"]
[SourceVersionDate "2020.05.31"]
[SourceQuality "1"]

1. f4 d5 2. Nf3 g6 3. g3 Bg7 4. Bg2 Nf6 5. d3 c5 6. 0-0 Nc6 7. c3 0-0 8. Qe1 d4 9. Na3 Be6 10. h3 Nd5 11. Bd2 h6 12. Nc2 Kh7 13. g4 f5 14. Qh4 Kg8 15. c4 fxg4 16. Ne5 Ne3 17. Nxc6 bxc6 18. Nxe3 dxe3 19. Bxe3 gxh3 20. Bxc6 Rb8 21. Rab1 Qd6 22. Be4 Kh7 23. Kh1 Bf5 24. Bf3 Rxb2 25. Rxb2 Bxb2 26. Qf2 Bd4 27. Rg1 e5 28. fxe5 Qxe5 29. Bxd4 cxd4 30. Qg3 Qf6 31. Kh2 h5 32. Rb1 Rf7 33. c5 h4 34. Qb8 Bxd3 35. Rb7 Bxe2 36. Rxf7+ Qxf7 37. Bxe2 Qf2+ 38. Kxh3 Qxe2 39. Qc7+ Kh6 40. Qf4+ Kg7 41. Qxd4+ Kf7 42. Qf4+ Ke6 43. Qd6+ Kf5 44. Qf8+ Kg5 45. Qd8+ Kf5 46. Qf8+ Kg5 47. Qd8+ Kf5 48. Qf8+ Kg5 1/2-1/2

[Event "Berlin Lichtenberger op 18th"]
[Site "Berlin"]
[Date "2019.08.25"]
[Round "9"]
[White "Krefenstein, Sergej"]
[Black "Rogozenco, Teodora Nana"]
[Result "1-0"]
[ECO "C41"]
[WhiteElo "2125"]
[BlackElo "1974"]
[PlyCount "59"]
[EventDate "2019.08.17"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. e4 d6 2. d4 Nf6 3. Nc3 e5 4. Nf3 Nbd7 5. Bc4 Be7 6. a4 0-0 7. 0-0 c6 8. h3 h6 9. Re1 Re8 10. a5 Qc7 11. Be3 Nf8 12. Qe2 Ng6 13. d5 Bd7 14. a6 c5 15. axb7 Qxb7 16. b3 a5 17. Nd2 Reb8 18. Ra2 Qb4 19. Na4 Ne8 20. Rea1 Bg5 21. Nb2 Bxe3 22. fxe3 Ra7 23. Nd3 Qb6 24. Qf2 Rba8 25. Nb2 Qb4 26. Na4 Nf6 27. Bd3 Qb8 28. Nc4 Ra6 29. Qe2 Nf8 30. Nxe5 1-0

[Event "Berlin Lichtenberger op 18th"]
[Site "Berlin"]
[Date "2019.08.24"]
[Round "8"]
[White "Hesse, Henrik"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "A20"]
[WhiteElo "2185"]
[BlackElo "2125"]
[PlyCount "73"]
[EventDate "2019.08.17"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. c4 e5 2. g3 Nf6 3. Bg2 c6 4. Nf3 e4 5. Nd4 Qb6 6. e3 d5 7. 0-0 Bc5 8. Nb3 Bd6 9. d3 Bg4 10. Qc2 Na6 11. dxe4 dxe4 12. Nc3 Nb4 13. Qb1 Be5 14. Nxe4 Be2 15. Nxf6+ Bxf6 16. Qe4+ Kf8 17. c5 Qb5 18. Bd2 Nd3 19. Bc3 Re8 20. Qf5 Bxc3 21. bxc3 Re5 22. Qc8+ Re8 23. Qd7 Ne5 24. Qd6+ Kg8 25. Nd4 Qd3 26. Rfb1 h5 27. Rxb7 Rh6 28. Qc7 Qxc3 29. Rab1 Bd3 30. Rd1 Bc4 31. Rb8 Rxb8 32. Qxb8+ Kh7 33. Qxe5 h4 34. Qe4+ Kg8 35. Qc2 Qb4 36. Rb1 Qxc5 37. Rb8+ 1-0

[Event "Berlin Lichtenberger op 18th"]
[Site "Berlin"]
[Date "2019.08.23"]
[Round "7"]
[White "Krefenstein, Sergej"]
[Black "Figura, Atila Gajo"]
[Result "1-0"]
[ECO "B42"]
[WhiteElo "2125"]
[BlackElo "2394"]
[PlyCount "51"]
[EventDate "2019.08.17"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 a6 5. Bd3 Bc5 6. Nb3 Be7 7. Qg4 g6 8. 0-0 d6 9. c4 h5 10. Qe2 Nd7 11. f4 h4 12. Nc3 b6 13. Be3 Bb7 14. a4 Nc5 15. Nxc5 bxc5 16. f5 gxf5 17. exf5 Nf6 18. fxe6 fxe6 19. Bg5 Kd7 20. Rae1 e5 21. Bxf6 Bxf6 22. Be4 Bxe4 23. Qxe4 Rf8 24. Qb7+ Ke6 25. Nd5 Rb8 26. Nf4+ 1-0

[Event "Berlin Lichtenberger op 18th"]
[Site "Berlin"]
[Date "2019.08.22"]
[Round "6"]
[White "Guenther, Thomas"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "E18"]
[WhiteElo "1985"]
[BlackElo "2125"]
[PlyCount "90"]
[EventDate "2019.08.17"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. d4 Nf6 2. Nf3 e6 3. c4 b6 4. g3 Bb7 5. Bg2 Be7 6. 0-0 0-0 7. Nc3 d6 8. d5 e5 9. e4 a5 10. Be3 Ng4 11. Bd2 Na6 12. Ne1 Nf6 13. f4 Nd7 14. f5 Bg5 15. Nf3 Bxd2 16. Qxd2 Nac5 17. Rfe1 Ba6 18. Bf1 h6 19. Qc2 Nf6 20. b3 Nh7 21. h4 Qe7 22. g4 Bb7 23. a3 a4 24. b4 Nb3 25. Rad1 Nd4 26. Qf2 Nxf3+ 27. Qxf3 Qxh4 28. Kg2 Qe7 29. Bd3 Ng5 30. Qf2 Nh7 31. Rh1 Bc8 32. Nb5 Qd8 33. c5 bxc5 34. bxc5 Ba6 35. c6 Bxb5 36. Bxb5 Qg5 37. Be2 Nf6 38. Qf3 Rfb8 39. Rb1 Rb3 40. Rxb3 axb3 41. Qxb3 Nxe4 42. Rh3 Qd2 43. Kf1 Qf4+ 44. Ke1 Qf2+ 45. Kd1 Qd4+ 0-1

[Event "Berlin Lichtenberger op 18th"]
[Site "Berlin"]
[Date "2019.08.21"]
[Round "5"]
[White "Krefenstein, Sergej"]
[Black "Syre, Christian"]
[Result "0-1"]
[ECO "B06"]
[WhiteElo "2125"]
[BlackElo "2198"]
[PlyCount "186"]
[EventDate "2019.08.17"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. e4 d6 2. d4 g6 3. Nc3 c6 4. Be3 Qb6 5. a3 Bg7 6. Nf3 Nf6 7. h3 0-0 8. Bd3 Nbd7 9. 0-0 Qc7 10. Qd2 a6 11. a4 c5 12. Rfe1 cxd4 13. Bxd4 e5 14. Be3 b6 15. Bg5 Bb7 16. Bf1 Rfc8 17. Rad1 Bf8 18. Qe3 Qc5 19. Qxc5 Rxc5 20. Nd2 Rac8 21. f3 h6 22. Be3 R5c7 23. Nb3 Kg7 24. Rd2 d5 25. Nxd5 Nxd5 26. exd5 Rxc2 27. Ree2 R2c4 28. a5 b5 29. Rd3 Rd8 30. Red2 Bb4 31. Rd1 Rc2 32. Bd2 Bd6 33. Bc3 b4 34. R1d2 Rxd2 35. Bxd2 Nf6 36. Be3 Rc8 37. Rd2 Ng8 38. Kf2 Ne7 39. g4 f5 40. gxf5 gxf5 41. f4 exf4 42. Bd4+ Kf7 43. Bb6 f3 44. Nd4 Bf4 45. Rc2 Rxc2+ 46. Nxc2 Nxd5 47. Bc4 Kg6 48. Bc5 Bc1 49. b3 Bd2 50. Bxd5 Bxd5 51. Nxb4 Bb7 52. Nd3 Bxa5 53. Ne5+ Kf6 54. Nxf3 Bc3 55. b4 Bxf3 56. Kxf3 Ke5 57. Bf8 Bd2 58. Ke2 Bc1 59. Kd3 Kd5 60. Kc2 Be3 61. Kd3 Bf4 62. Bg7 h5 63. Bc3 Bc1 64. Bg7 f4 65. Bh6 Be3 66. Bg7 Bc1 67. Bh6 Ke5 68. Bg7+ Kf5 69. Bf8 Be3 70. Bh6 Bb6 71. Bf8 Bc7 72. Be7 Be5 73. Bc5 Bf6 74. Bf2 Be7 75. Be1 Bd6 76. Bc3 Bf8 77. Be1 Be7 78. Kd4 Bg5 79. Bf2 f3 80. Be3 Bxe3+ 81. Kxe3 Ke5 82. Kxf3 Kd4 83. h4 Kc4 84. Kf4 Kxb4 85. Kg5 a5 86. Kxh5 a4 87. Kg6 a3 88. h5 a2 89. h6 a1Q 90. Kh7 Qa7+ 91. Kg8 Qb8+ 92. Kg7 Qe5+ 93. Kh7 Qg5 0-1

[Event "Berlin Lichtenberger op 18th"]
[Site "Berlin"]
[Date "2019.08.20"]
[Round "4"]
[White "Krefenstein, Sergej"]
[Black "Bergmann, Jens"]
[Result "1-0"]
[ECO "B01"]
[WhiteElo "2125"]
[BlackElo "1829"]
[PlyCount "36"]
[EventDate "2019.08.17"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. e4 d5 2. exd5 Qxd5 3. Nc3 Qa5 4. d4 c6 5. Nf3 Nf6 6. Bc4 b5 7. Bb3 b4 8. Ne2 Nbd7 9. 0-0 e6 10. Re1 Bd6 11. Nf4 0-0 12. Nxe6 fxe6 13. Rxe6 Nd5 14. Rxd6 Qc7 15. Rxd5 cxd5 16. Bxd5+ Kh8 17. Bxa8 Nf6 18. Ne5 Ne4 1-0

[Event "Berlin Lichtenberger op 18th"]
[Site "Berlin"]
[Date "2019.08.19"]
[Round "3"]
[White "Hoffbauer, Joerg"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "A40"]
[WhiteElo "1773"]
[BlackElo "2125"]
[PlyCount "58"]
[EventDate "2019.08.17"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 e6 3. a3 b6 4. Nc3 Bb7 5. f3 d5 6. e3 Be7 7. b3 0-0 8. Bd3 c5 9. Nge2 Nc6 10. dxc5 dxc4 11. Bxc4 Bxc5 12. b4 Bd6 13. Bb3 Qb8 14. f4 Rd8 15. Qc2 Bxb4 16. 0-0 Bc5 17. Ng3 Na5 18. Ba2 Ba6 19. Rf3 Qc7 20. Kh1 Bd3 21. Qb2 Rac8 22. Bd2 Qd6 23. Rd1 Bxa3 24. Qa1 Bc2 25. Nb5 Qe7 26. Rff1 Bxd1 27. Rxd1 Rxd2 28. Nxa3 Rxd1+ 29. Qxd1 Qxa3 0-1

[Event "Berlin Lichtenberger op 18th"]
[Site "Berlin"]
[Date "2019.08.18"]
[Round "2"]
[White "Krefenstein, Sergej"]
[Black "Ahlers, Knut"]
[Result "1/2-1/2"]
[ECO "C45"]
[WhiteElo "2125"]
[BlackElo "1880"]
[PlyCount "141"]
[EventDate "2019.08.17"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Nxd4 g6 5. Nxc6 bxc6 6. Qd4 Qf6 7. Be3 Bg7 8. c3 Ne7 9. Nd2 0-0 10. Qxf6 Bxf6 11. Be2 a5 12. 0-0-0 a4 13. Kc2 d5 14. Bc5 Re8 15. Rhe1 Bg7 16. Bf3 Be6 17. Bxe7 Rxe7 18. exd5 cxd5 19. Bxd5 Bf5+ 20. Ne4 Ra5 21. f3 a3 22. b4 Rb5 23. g4 Bc8 24. Bc4 Rb8 25. Rd8+ Bf8 26. Nf6+ Kg7 27. Ne8+ Kg8 28. Red1 Rxe8 29. Rxe8 Bf5+ 30. gxf5 Rxe8 31. Kb3 Bd6 32. h3 Re3 33. Rd3 Rxd3 34. Bxd3 Be5 35. Kxa3 Bxc3 36. Kb3 Bd2 37. Kc4 Kg7 38. a4 Kf6 39. fxg6 fxg6 40. a5 Ke6 41. Kc5 Kd7 42. a6 Be3+ 43. Kd5 Bb6 44. Bb5+ Kc8 45. Ke6 g5 46. Kf5 Be3 47. Kg4 Kb8 48. Bd3 h6 49. Bf5 Ka7 50. b5 Kb6 51. Bd7 Bd2 52. h4 Bf4 53. h5 c5 54. bxc6 Kxa6 55. Kf5 Kb6 56. Kg6 g4 57. Bxg4 Kxc6 58. Kf5 Bd2 59. Ke5 Bc3+ 60. Ke6 Bd2 61. Bf5 Kc5 62. Be4 Kd4 63. Kf5 Be3 64. f4 Bd2 65. Bb7 Bc1 66. Kg4 Bd2 67. Kf3 Bc1 68. Kg4 Bd2 69. f5 Ke5 70. Bc8 Kf6 71. Be6 1/2-1/2

[Event "Berlin Lichtenberger op 18th"]
[Site "Berlin"]
[Date "2019.08.17"]
[Round "1"]
[White "Glienke, Michael"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "E12"]
[WhiteElo "1754"]
[BlackElo "2125"]
[PlyCount "146"]
[EventDate "2019.08.17"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. d4 Nf6 2. Bf4 e6 3. c4 b6 4. Nf3 Bb7 5. e3 Be7 6. Be2 Nh5 7. Bg3 0-0 8. Nc3 d6 9. Qc2 Nd7 10. d5 g6 11. dxe6 fxe6 12. Nd4 Ng7 13. Bf3 Bxf3 14. Nxf3 e5 15. h3 Nf5 16. Bh2 Nc5 17. 0-0 a5 18. Rad1 Qe8 19. Nd5 Bd8 20. a3 a4 21. Nd2 Qf7 22. Ne4 Ne6 23. Ng3 Bh4 24. Ne4 Qg7 25. Qe2 Bd8 26. Ndc3 Qf7 27. Nb5 Ng5 28. Nxg5 Bxg5 29. Qd3 Bf6 30. Qd5 Ra5 31. Qc6 Bd8 32. e4 Ng7 33. Rd3 Qe8 34. Qxe8 Rxe8 35. f3 Ne6 36. Rfd1 Bg5 37. Kf1 Re7 38. Bg3 Nc5 39. Rc3 Kf7 40. Ke2 Ra8 41. Bf2 Ne6 42. g3 Rd7 43. Be3 h6 44. h4 Bxe3 45. Kxe3 Ke7 46. Rc2 c6 47. Nc3 Nd4 48. Rf2 h5 49. Ne2 Ne6 50. Nc3 Ra5 51. Rfd2 Nc5 52. f4 Nb3 53. Rd3 Nc5 54. R3d2 Ke6 55. Ne2 Nb3 56. Rd3 Nc5 57. R3d2 b5 58. f5+ gxf5 59. exf5+ Ke7 60. f6+ Ke6 61. f7 Ra8 62. cxb5 cxb5 63. Nc3 Rf8 64. Nxb5 Nb7 65. Rf1 Rfxf7 66. Rxf7 Rxf7 67. Rc2 Nc5 68. Rg2 Rb7 69. Nc3 d5 70. Nd1 d4+ 71. Ke2 Rg7 72. Kf3 e4+ 73. Kf4 Rg4# 0-1

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2019.06.30"]
[Round "9"]
[White "Krefenstein, Sergej"]
[Black "Seitz, Manuel"]
[Result "1-0"]
[ECO "C45"]
[WhiteElo "2158"]
[BlackElo "1741"]
[PlyCount "45"]
[EventDate "2019.06.22"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2022"]
[Source "ChessBase"]
[SourceDate "2021.10.06"]
[SourceVersion "1"]
[SourceVersionDate "2021.10.06"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Nxd4 Bc5 5. Nxc6 bxc6 6. Bd3 Nf6 7. 0-0 0-0 8. e5 Nd5 9. a3 d6 10. b4 Bb6 11. c4 Ne7 12. Bb2 Bf5 13. Bxf5 Nxf5 14. Qg4 Nh6 15. Qf3 c5 16. Rd1 Qe7 17. exd6 cxd6 18. Nc3 cxb4 19. axb4 Rac8 20. Nd5 Qd7 21. Nf6+ gxf6 22. Qxf6 Bxf2+ 23. Kh1 1-0

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2019.06.29"]
[Round "8"]
[White "Groot, Patrick"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "E33"]
[WhiteElo "1964"]
[BlackElo "2158"]
[PlyCount "147"]
[EventDate "2019.06.22"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2022"]
[Source "ChessBase"]
[SourceDate "2021.10.06"]
[SourceVersion "1"]
[SourceVersionDate "2021.10.06"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 Nc6 5. Nf3 0-0 6. Bd2 d6 7. a3 Bxc3 8. Bxc3 Qe7 9. e4 e5 10. d5 Nb8 11. Be2 a5 12. b3 Bg4 13. h3 Bh5 14. 0-0 Nbd7 15. b4 Bg6 16. Nd2 c6 17. Bd3 cxd5 18. cxd5 Rfc8 19. Rfc1 Rc7 20. Qb3 a4 21. Qa2 Nb6 22. Qb1 Rac8 23. Bb2 Nbxd5 24. Rxc7 Nxc7 25. Qc2 Rd8 26. Rc1 Ne6 27. f3 Nf4 28. Bb5 N6d5 29. Nf1 Qg5 30. Kh1 Nb6 31. Qf2 Nc8 32. Rc7 b6 33. Bc1 Qf6 34. Qc2 Ne7 35. Bxf4 exf4 36. Ra7 Nd5 37. Qc6 Ne3 38. Qxb6 Nxf1 39. Bxf1 h5 40. Rc7 Qa1 41. Kg1 Qxa3 42. Bc4 Qc1+ 43. Kh2 Qe3 44. Qxe3 fxe3 45. b5 Rb8 46. Ra7 Kf8 47. Rxa4 f5 48. Ra3 e2 49. Re3 fxe4 50. fxe4 Ke7 51. Kg3 Bf7 52. Bxe2 g5 53. Ra3 Kf6 54. Kf2 h4 55. Ke3 Be8 56. Kd4 Rb7 57. Rb3 Rb6 58. Rb2 Bd7 59. Ra2 Rb7 60. Rb2 Rb6 61. Bc4 Be6 62. Bd5 Ke7 63. Bc6 Bd7 64. Rc2 Be6 65. e5 g4 66. hxg4 Bxg4 67. Ra2 dxe5+ 68. Kxe5 h3 69. Ra7+ Kd8 70. Kd6 hxg2 71. Rg7 Be6 72. Kxe6 Rb8 73. Kd6 g1Q 74. Rxg1 1-0

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2019.06.28"]
[Round "7"]
[White "Krefenstein, Sergej"]
[Black "Silz, Elisa"]
[Result "0-1"]
[ECO "B26"]
[WhiteElo "2158"]
[BlackElo "1977"]
[PlyCount "88"]
[EventDate "2019.06.22"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2022"]
[Source "ChessBase"]
[SourceDate "2021.10.06"]
[SourceVersion "1"]
[SourceVersionDate "2021.10.06"]
[SourceQuality "1"]

1. e4 c5 2. Nc3 d6 3. g3 Nc6 4. Bg2 g6 5. d3 Bg7 6. Be3 Nf6 7. h3 0-0 8. Nge2 e5 9. Qd2 Nd4 10. g4 Bd7 11. Ng3 b5 12. g5 Ne8 13. Nd5 Bc6 14. 0-0 Ne6 15. c3 Bxd5 16. exd5 Nf4 17. Bxf4 exf4 18. Qxf4 f6 19. Ne4 fxg5 20. Qxg5 Nf6 21. Qg3 Nxe4 22. dxe4 Rb8 23. f4 b4 24. e5 bxc3 25. bxc3 Qc7 26. Rfe1 c4 27. Re2 Rb7 28. h4 Qc8 29. Kh2 Bh6 30. Rf1 Rb1 31. Rff2 Kh8 32. e6 Qc7 33. Be4 Rbb8 34. Qg4 Qe7 35. Kg3 Rf6 36. Rf3 Rbf8 37. Ref2 Bg7 38. h5 gxh5 39. Qg5 Bh6 40. Qxh5 Rg8+ 41. Kh2 Qg7 42. Bf5 Bxf4+ 43. Kh3 Rxf5 44. Qxf5 Qh6+ 0-1

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2019.06.27"]
[Round "6"]
[White "Tschernatsch, Johannes"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "B19"]
[WhiteElo "2029"]
[BlackElo "2158"]
[PlyCount "53"]
[EventDate "2019.06.22"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2022"]
[Source "ChessBase"]
[SourceDate "2021.10.06"]
[SourceVersion "1"]
[SourceVersionDate "2021.10.06"]
[SourceQuality "1"]

1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. Nf3 Nd7 7. h4 h6 8. h5 Bh7 9. Bd3 Bxd3 10. Qxd3 e6 11. Bd2 Ngf6 12. 0-0-0 Be7 13. Kb1 Qb6 14. Ne5 Rd8 15. Qe2 0-0 16. c4 c5 17. Bc3 cxd4 18. Bxd4 Qc7 19. f4 Rc8 20. b3 Bc5 21. Bb2 Rfe8 22. Ne4 Be7 23. Nxd7 Nxd7 24. Qg4 g6 25. hxg6 f5 26. Rxh6 Ne5 27. Qh5 1-0

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2019.06.26"]
[Round "5"]
[White "Krefenstein, Sergej"]
[Black "Lopez Gomez, Jose Pablo"]
[Result "1-0"]
[ECO "C06"]
[WhiteElo "2158"]
[BlackElo "2065"]
[PlyCount "59"]
[EventDate "2019.06.22"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2022"]
[Source "ChessBase"]
[SourceDate "2021.10.06"]
[SourceVersion "1"]
[SourceVersionDate "2021.10.06"]
[SourceQuality "1"]

1. e4 e6 2. d4 d5 3. Nd2 Nf6 4. e5 Nfd7 5. Bd3 c5 6. c3 Nc6 7. Ne2 cxd4 8. cxd4 f6 9. exf6 Nxf6 10. 0-0 Bd6 11. Nf3 Qc7 12. h3 0-0 13. Be3 Bd7 14. Re1 Rae8 15. Nc3 a6 16. Rc1 Qb8 17. Na4 e5 18. dxe5 Nxe5 19. Nxe5 Bxe5 20. Nc5 Bc8 21. b4 Kh8 22. Bb1 Bh2+ 23. Kh1 Qd6 24. Qd4 Be5 25. Qh4 Qe7 26. Bg6 Bb8 27. Bxe8 Qxe8 28. Bf4 Ne4 29. Bxb8 g5 30. Qh6 1-0

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2019.06.25"]
[Round "4"]
[White "Vogel, Constantin"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "A20"]
[WhiteElo "2073"]
[BlackElo "2158"]
[PlyCount "53"]
[EventDate "2019.06.22"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2022"]
[Source "ChessBase"]
[SourceDate "2021.10.06"]
[SourceVersion "1"]
[SourceVersionDate "2021.10.06"]
[SourceQuality "1"]

1. c4 e5 2. g3 c6 3. d4 e4 4. Bg2 d5 5. Nc3 Nf6 6. cxd5 cxd5 7. Nh3 Nbd7 8. 0-0 Be7 9. Qb3 Nb6 10. Bg5 h6 11. Bxf6 Bxf6 12. Nf4 Be6 13. a4 Qd7 14. a5 Nc4 15. Nxe6 fxe6 16. Nxe4 Bxd4 17. Rfd1 Bxb2 18. Nc5 Qe7 19. Nxe6 Bxa1 20. Bxd5 Nd6 21. Qa4+ Qd7 22. Qxa1 Ke7 23. Qxg7+ Nf7 24. Nf4 Raf8 25. Ng6+ Ke8 26. Bxf7+ Qxf7 27. Qe5+ 1-0

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2019.06.24"]
[Round "3"]
[White "Krefenstein, Sergej"]
[Black "Dathe, Frederick"]
[Result "1-0"]
[ECO "B38"]
[WhiteElo "2158"]
[BlackElo "2074"]
[PlyCount "107"]
[EventDate "2019.06.22"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2022"]
[Source "ChessBase"]
[SourceDate "2021.10.06"]
[SourceVersion "1"]
[SourceVersionDate "2021.10.06"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. c4 Bg7 6. Be3 Nf6 7. Nc3 d6 8. Be2 0-0 9. 0-0 Bd7 10. Qd2 Nxd4 11. Bxd4 Bc6 12. f3 a5 13. Nd5 Bxd5 14. cxd5 Nd7 15. Be3 Nc5 16. Rac1 Qb6 17. b3 Rfc8 18. Rc4 Qd8 19. Rc2 Qb6 20. Rfc1 Qb4 21. Qxb4 axb4 22. Bd2 Bc3 23. Bxc3 bxc3 24. Bc4 Ra3 25. Rf2 Nd7 26. Bb5 Ne5 27. h3 Rc5 28. Bf1 b5 29. f4 Nd7 30. b4 Rc8 31. Bxb5 Nf6 32. Bd3 Ra4 33. Rb1 Rca8 34. Rb3 Nd7 35. Bb5 Rxa2 36. Rxc3 Nf6 37. Bd3 Ra1+ 38. Rf1 Nh5 39. f5 Nf4 40. fxg6 hxg6 41. Bc4 e6 42. Rc2 exd5 43. Bxd5 Nxd5 44. exd5 Rxf1+ 45. Kxf1 Rb8 46. Rc4 Kg7 47. Ke2 Rb5 48. Rd4 Kf6 49. Kd3 Ke5 50. Kc3 g5 51. Rd2 Rxd5 52. Rxd5+ Kxd5 53. Kd3 f5 54. g3 1-0

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2019.06.23"]
[Round "2"]
[White "Kutschke, Jens"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "B12"]
[WhiteElo "1947"]
[BlackElo "2158"]
[PlyCount "102"]
[EventDate "2019.06.22"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2022"]
[Source "ChessBase"]
[SourceDate "2021.10.06"]
[SourceVersion "1"]
[SourceVersionDate "2021.10.06"]
[SourceQuality "1"]

1. e4 c6 2. d4 d5 3. e5 Bf5 4. Bd3 Bxd3 5. Qxd3 e6 6. Ne2 Qa5+ 7. Nd2 Qa6 8. Qxa6 Nxa6 9. c3 c5 10. a3 c4 11. 0-0 Ne7 12. b3 cxb3 13. Rb1 Nc6 14. c4 dxc4 15. Nxc4 0-0-0 16. Be3 Nc7 17. Rfc1 Kb8 18. Rxb3 Nd5 19. Bg5 Rd7 20. Ne3 Nb6 21. a4 h6 22. d5 Nxd5 23. Nxd5 Rxd5 24. Bf4 Bb4 25. h3 a5 26. Bg3 Rhd8 27. Kh2 Rd3 28. Rbb1 Ra3 29. Ra1 Rxa1 30. Rxa1 Rd2 31. Nf4 Bc3 32. Ra3 Bxe5 33. Rf3 Nd4 34. Re3 Bc7 35. Rc3 Nc6 36. Nh5 g6 37. Nf6 Rxf2 38. Bxc7+ Kxc7 39. Ng4 Rf4 40. Nxh6 f5 41. Ra3 e5 42. Nf7 Rd4 43. Ng5 Kd6 44. Nf3 Rb4 45. g3 Rb2+ 46. Kg1 e4 47. Nh4 Ne5 48. Ra1 Ke6 49. Ng2 g5 50. Kf1 Rb3 51. h4 Rf3+ 0-1

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2019.06.22"]
[Round "1"]
[White "Krefenstein, Sergej"]
[Black "Jeremic, Nemanja"]
[Result "1-0"]
[ECO "C42"]
[WhiteElo "2158"]
[BlackElo "1727"]
[PlyCount "60"]
[EventDate "2019.06.22"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2022"]
[Source "ChessBase"]
[SourceDate "2021.10.06"]
[SourceVersion "1"]
[SourceVersionDate "2021.10.06"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. Nc3 Nxc3 6. dxc3 Bg4 7. Be3 Nd7 8. h3 Be6 9. Qd2 Be7 10. Nd4 0-0 11. 0-0-0 Nf6 12. Nxe6 fxe6 13. Bc4 Qd7 14. Qe2 Kh8 15. g4 e5 16. g5 Ng8 17. Bd3 Qa4 18. c4 Qc6 19. Qg4 Qf3 20. Be4 Qxg4 21. hxg4 g6 22. Bxg6 Kg7 23. Be4 Rf7 24. Rxh7+ Kf8 25. g6 Rg7 26. g5 c6 27. Rdh1 d5 28. cxd5 cxd5 29. Rxg7 Kxg7 30. Rh7+ Kf8 1-0

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2019.04.28"]
[Round "9"]
[White "Dimitrijeski, Kristian"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "E33"]
[WhiteElo "2164"]
[BlackElo "2123"]
[PlyCount "128"]
[EventDate "2019.04.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 Nc6 5. Nf3 d6 6. e3 0-0 7. Bd2 Qe7 8. Be2 e5 9. d5 Nb8 10. 0-0 a5 11. b3 Bg4 12. a3 Bxc3 13. Bxc3 Nbd7 14. Rfe1 Rfe8 15. Bb2 Bh5 16. e4 Bg6 17. Nd2 h5 18. b4 h4 19. h3 Nh5 20. Bxh5 Bxh5 21. Nf1 axb4 22. axb4 Qg5 23. Nh2 Nf8 24. c5 Ng6 25. Rxa8 Rxa8 26. Bc1 Nf4 27. Bxf4 Qxf4 28. cxd6 cxd6 29. Nf1 Bg6 30. f3 Qg5 31. Qd2 Qd8 32. Kh2 f5 33. exf5 Bxf5 34. f4 Qf6 35. fxe5 dxe5 36. d6 Be6 37. Qe3 Rd8 38. Nd2 Bd5 39. Qxe5 Qxd6 40. Qxd6 Rxd6 41. Nf3 Bxf3 42. gxf3 Rd2+ 43. Kg1 Rd4 44. Re4 Rxe4 45. fxe4 Kf7 46. Kf2 Kf6 47. Kf3 Ke5 48. Kg4 Kxe4 49. Kxh4 Kf4 50. Kh5 Kf5 51. b5 b6 52. h4 g6+ 53. Kh6 Kf6 54. Kh7 g5 55. hxg5+ Kxg5 56. Kg7 Kf5 57. Kh6 Ke5 58. Kg5 Kd5 59. Kf5 Kc5 60. Ke5 Kxb5 61. Kd4 Kb4 62. Kd3 Kb3 63. Kd2 Kb2 64. Kd3 b5 0-1

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2019.04.27"]
[Round "8"]
[White "Krefenstein, Sergej"]
[Black "Gebigke, Martin"]
[Result "1-0"]
[ECO "B90"]
[WhiteElo "2123"]
[BlackElo "2068"]
[PlyCount "121"]
[EventDate "2019.04.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. f3 e5 7. Nb3 Be6 8. Be3 Nbd7 9. g4 Be7 10. Qd2 0-0 11. 0-0-0 Nb6 12. g5 Nh5 13. Rg1 Qc7 14. Kb1 d5 15. exd5 Nxd5 16. Nxd5 Bxd5 17. Qf2 Be6 18. Bd3 Rfe8 19. Bb6 Qc8 20. Qe3 Bf8 21. Nd2 Nf4 22. Ne4 Kh8 23. Nc3 Bb4 24. Qe4 Nxd3 25. Rxd3 Bc5 26. Bxc5 Qxc5 27. Rgd1 g6 28. Qh4 Rac8 29. R3d2 Bf5 30. Ne4 Bxe4 31. Qxe4 Rc7 32. Rd5 Qe7 33. h4 Kg7 34. Re1 Rc5 35. Rxc5 Qxc5 36. f4 b5 37. fxe5 Re6 38. Qf4 a5 39. Rf1 Qe7 40. Re1 Qc5 41. a3 b4 42. axb4 axb4 43. Rf1 Qe7 44. Qf6+ Kg8 45. Qxe7 Rxe7 46. Re1 b3 47. cxb3 Rb7 48. Re4 Rxb3 49. Kc2 Rh3 50. b4 Kf8 51. b5 Ke7 52. b6 Rh2+ 53. Kc3 Rh3+ 54. Kb4 Kd7 55. Rc4 Rh1 56. Kb5 Rb1+ 57. Ka6 Ra1+ 58. Kb7 Rd1 59. Kb8 Kd8 60. b7 Kd7 61. Ra4 1-0

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2019.04.26"]
[Round "7"]
[White "Boettcher, Patrick"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "A35"]
[WhiteElo "2076"]
[BlackElo "2123"]
[PlyCount "41"]
[EventDate "2019.04.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. Nc3 Nc6 6. Nf3 g6 7. cxd5 Nxd5 8. Qb3 e6 9. Bc4 Nb6 10. Bb5 Bd7 11. 0-0 a6 12. Bxc6 Bxc6 13. Ne5 Bg7 14. Nxc6 bxc6 15. Be3 0-0 16. Rfd1 Nd5 17. Ne4 Rb8 18. Qc2 Qb6 19. b3 Rfd8 20. Nc5 Bf8 21. Rac1 1/2-1/2

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2019.04.25"]
[Round "6"]
[White "Krefenstein, Sergej"]
[Black "Heerde, Thomas"]
[Result "1-0"]
[ECO "B34"]
[WhiteElo "2123"]
[BlackElo "2027"]
[PlyCount "65"]
[EventDate "2019.04.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 g6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 Bg7 6. e5 Ng8 7. Bf4 Nc6 8. Nxc6 bxc6 9. Bc4 Qa5 10. Qf3 f6 11. e6 Qc5 12. exd7+ Bxd7 13. Qe2 e5 14. 0-0-0 Bf5 15. Rhe1 Ne7 16. Be3 Qa5 17. g4 Bd7 18. f4 Rb8 19. fxe5 Qb4 20. exf6 Qxb2+ 21. Kd2 Bxf6 22. Bd4 Bg5+ 23. Kd3 Rf8 24. Rb1 Qxb1 25. Rxb1 Rxb1 26. Nxb1 Rf4 27. h3 Bh4 28. Nd2 h5 29. Qe5 Bg3 30. Qe3 hxg4 31. Bc5 Bf5+ 32. Kc3 Rxc4+ 33. Nxc4 1-0

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2019.04.24"]
[Round "5"]
[White "Meyer Dunker, Paul"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "B13"]
[WhiteElo "2030"]
[BlackElo "2123"]
[PlyCount "74"]
[EventDate "2019.04.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. e4 c6 2. d4 d5 3. exd5 cxd5 4. Bd3 Nc6 5. c3 Qc7 6. Ne2 Bg4 7. f3 Bd7 8. Na3 a6 9. Nc2 Nf6 10. Bf4 e5 11. dxe5 Nxe5 12. Ncd4 Bd6 13. 0-0 0-0 14. Kh1 g6 15. Ng3 Kg7 16. Qd2 Rfe8 17. Rae1 Ng8 18. Bb1 Re7 19. Bg5 Nc4 20. Bh6+ Kh8 21. Qg5 Rxe1 22. Rxe1 Nxh6 23. Qxh6 Bf8 24. Qc1 Re8 25. Rxe8 Bxe8 26. f4 Bd6 27. Nge2 Qe7 28. Bd3 Ne3 29. Nf3 Ng4 30. Kg1 Bd7 31. h3 Nf6 32. Qd1 Qe3+ 33. Kh1 Bxh3 34. Qc1 Qxd3 35. Ned4 Bg4 36. Ng5 Kg7 37. Qe1 Bxf4 0-1

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2019.04.23"]
[Round "4"]
[White "Krefenstein, Sergej"]
[Black "Zschaebitz, Klaus"]
[Result "0-1"]
[ECO "C03"]
[WhiteElo "2123"]
[BlackElo "2024"]
[PlyCount "66"]
[EventDate "2019.04.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. e4 e6 2. d4 d5 3. Nd2 h6 4. Ngf3 c5 5. exd5 exd5 6. c3 Nf6 7. Bd3 Nc6 8. dxc5 Bxc5 9. 0-0 0-0 10. Nb3 Bb6 11. Bf4 Bg4 12. Bc2 Ne4 13. Qd3 Bxf3 14. Qxf3 g5 15. Bg3 f5 16. h3 Qf6 17. Bh2 Rad8 18. Rad1 Qg6 19. Kh1 h5 20. Nd4 Rf7 21. Qe2 Re7 22. Qb5 g4 23. Bxe4 fxe4 24. Ne2 Qf7 25. Nf4 Red7 26. c4 Nd4 27. Rxd4 Bxd4 28. cxd5 Be5 29. Ne6 Bxh2 30. Nxd8 Rxd8 31. Kxh2 Rxd5 32. Qc4 gxh3 33. Kxh3 Rd3+ 0-1

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2019.04.22"]
[Round "3"]
[White "Nogly, Christoph"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "E07"]
[WhiteElo "2225"]
[BlackElo "2123"]
[PlyCount "117"]
[EventDate "2019.04.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 e6 3. g3 Bb4+ 4. Bd2 Be7 5. Bg2 d5 6. Nf3 0-0 7. 0-0 c6 8. Nc3 Nbd7 9. Bf4 dxc4 10. e4 b5 11. d5 exd5 12. exd5 cxd5 13. Nxd5 Nxd5 14. Qxd5 Nb6 15. Qxd8 Rxd8 16. Ne5 Bf5 17. Bxa8 Rxa8 18. Nc6 Bf6 19. Be5 Bxe5 20. Nxe5 Rc8 21. Rfd1 f6 22. Nf3 Bg4 23. Kg2 c3 24. bxc3 Rxc3 25. Rd8+ Kf7 26. Ne1 Be2 27. Rd2 Bc4 28. f3 Bd5 29. Rad1 Ke6 30. Rd3 Rc7 31. Rb1 Bc4 32. Rd2 Nd5 33. Nc2 Nc3 34. Re1+ Kf7 35. Ne3 Be6 36. Rc1 b4 37. Nd1 Bf5 38. g4 Bg6 39. h4 h6 40. h5 Bh7 41. a3 a5 42. axb4 axb4 43. Rd4 Rb7 44. Nxc3 bxc3 45. Rxc3 Bb1 46. Rd8 f5 47. Rcc8 fxg4 48. Rf8+ Ke6 49. fxg4 Be4+ 50. Kg3 Re7 51. Rf4 Bd5 52. Rc3 Rb7 53. Re3+ Kd6 54. Rd4 Kc5 55. Rd2 Rd7 56. Re5 Rd6 57. Kf4 Rf6+ 58. Rf5 Rd6 59. Rfxd5+ 1-0

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2019.04.21"]
[Round "2"]
[White "Lachmann, Utz"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "B12"]
[WhiteElo "2188"]
[BlackElo "2123"]
[PlyCount "122"]
[EventDate "2019.04.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. e4 c6 2. d4 d5 3. e5 Bf5 4. Nc3 e6 5. g4 Bg6 6. Nge2 c5 7. Be3 Nc6 8. h4 h5 9. Nf4 Bxc2 10. Qxc2 cxd4 11. Bxd4 Nxd4 12. Qa4+ Nc6 13. Nxh5 g6 14. Ng3 Bc5 15. Bb5 Nge7 16. 0-0-0 Qc7 17. f4 Bf2 18. Rd3 0-0-0 19. Kb1 a6 20. Bxc6 Nxc6 21. Nce2 Kb8 22. h5 g5 23. fxg5 Nxe5 24. Rc3 Nc6 25. Rf1 Ba7 26. g6 fxg6 27. hxg6 Rhf8 28. Rff3 Rxf3 29. Rxf3 Qg7 30. Qf4+ Ne5 31. Ka1 Qc7 32. Rc3 Qd6 33. g7 Rg8 34. Nh5 d4 35. Rd3 Qc7 36. Rd1 d3 37. Nc3 Bc5 38. Ne4 Bd4 39. Rc1 Qe7 40. Nc3 Qb4 41. a3 Qd6 42. Rf1 Ka7 43. Qf8 Qc6 44. Qb4 Bc5 45. Qe4 Qc7 46. Ka2 Bxa3 47. Kxa3 Nc4+ 48. Kb4 a5+ 49. Ka4 Qc5 50. Nb5+ Ka6 51. Qxe6+ b6 52. Nc7+ Qxc7 53. Qd5 Nxb2+ 54. Ka3 Qc3+ 55. Qb3 Nc4+ 56. Ka2 Qxb3+ 57. Kxb3 Nd2+ 58. Kc3 Nxf1 59. Kxd3 Nh2 60. g5 Nf3 61. Ke4 Nxg5+ 0-1

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2019.04.20"]
[Round "1"]
[White "Krefenstein, Sergej"]
[Black "Florstedt, Johannes"]
[Result "0-1"]
[ECO "B90"]
[WhiteElo "2123"]
[BlackElo "2322"]
[PlyCount "82"]
[EventDate "2019.04.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. f3 e5 7. Nb3 Be6 8. Be3 h5 9. Qd2 Nbd7 10. Nd5 Bxd5 11. exd5 g6 12. Be2 Bg7 13. 0-0 0-0 14. c4 b6 15. Rad1 Re8 16. Nc1 e4 17. f4 Ng4 18. Bxg4 hxg4 19. Ne2 f5 20. Nd4 Bxd4 21. Qxd4 a5 22. b3 Nc5 23. Bd2 Ra7 24. Bc3 Rh7 25. g3 Nd3 26. Bd2 Qc7 27. Be3 Qc5 28. Qxd3 exd3 29. Bxc5 bxc5 30. Rfe1 Re4 31. Kg2 Kf8 32. Kg1 Ke8 33. Rf1 Re2 34. h4 gxh3 35. Rxd3 Rhe7 36. Rf2 Rxf2 37. Kxf2 Re1 38. Kxe1 h2 39. Kd2 h1Q 40. a4 Qg2+ 41. Kc3 Qf2 0-1

[Event "Oberliga Nord O 1819"]
[Site "Germany"]
[Date "2019.04.07"]
[Round "9.2"]
[White "Krefenstein, Sergej"]
[Black "Leisner, Hannes"]
[Result "1-0"]
[ECO "B42"]
[WhiteElo "2116"]
[BlackElo "2296"]
[PlyCount "81"]
[EventDate "2018.10.21"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]
[WhiteTeam "Berlin Makkabi"]
[BlackTeam "Greifswald"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 a6 5. Bd3 Bc5 6. Nb3 Be7 7. 0-0 d6 8. f4 Qc7 9. Qf3 Nd7 10. N1d2 Ngf6 11. Qg3 b6 12. Nf3 Bb7 13. e5 Nh5 14. Qh3 g6 15. Bd2 0-0 16. Nbd4 Ng7 17. Rae1 Nc5 18. Qh6 Nxd3 19. cxd3 dxe5 20. fxe5 Bxf3 21. Nxf3 Nf5 22. Qf4 Rad8 23. d4 Nxd4 24. Ng5 Nf5 25. g4 Rd4 26. Ne4 Ng7 27. Nf6+ Bxf6 28. Qxd4 Be7 29. Qc3 Qd7 30. Be3 Rc8 31. Qd2 Qa4 32. Qg2 h5 33. h3 hxg4 34. hxg4 Qxa2 35. Qf2 Rf8 36. Bxb6 Qc4 37. Qd4 Qb3 38. Re3 Qb5 39. Ref3 Qd5 40. Qf2 Qxe5 41. Rxf7 1-0

[Event "Oberliga Nord O 1819"]
[Site "Germany"]
[Date "2019.03.24"]
[Round "8.2"]
[White "Dettmann, Gerd"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "B13"]
[WhiteElo "2155"]
[BlackElo "2116"]
[PlyCount "50"]
[EventDate "2018.10.21"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]
[WhiteTeam "Guestrow/Teterow"]
[BlackTeam "Berlin Makkabi"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. e4 c6 2. d4 d5 3. exd5 cxd5 4. Nf3 Nf6 5. Ne5 g6 6. Nd2 Bg7 7. Bd3 Nc6 8. Ndf3 0-0 9. c3 Ne8 10. 0-0 f6 11. Nxc6 bxc6 12. Re1 Nd6 13. Bf4 Bg4 14. Be2 Re8 15. h3 Bf5 16. Qa4 e5 17. dxe5 fxe5 18. Be3 Qc7 19. Rad1 Reb8 20. Bc1 Ne4 21. Rf1 Bf8 22. Nh4 Nc5 23. Qa3 Bc2 24. Rde1 Nd3 25. b4 a5 0-1

[Event "Oberliga Nord O 1819"]
[Site "Germany"]
[Date "2019.02.24"]
[Round "7.2"]
[White "Krefenstein, Sergej"]
[Black "Hansch, Karsten"]
[Result "0-1"]
[ECO "B90"]
[WhiteElo "2116"]
[BlackElo "2262"]
[PlyCount "88"]
[EventDate "2018.10.21"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]
[WhiteTeam "Berlin Makkabi"]
[BlackTeam "Potsdam Empor"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. f3 e5 7. Nb3 Be6 8. Be3 h5 9. Qd2 Nbd7 10. 0-0-0 b5 11. Kb1 Rc8 12. Qf2 g6 13. h3 Qc7 14. Rg1 h4 15. Bd3 b4 16. Nd5 Bxd5 17. exd5 Ra8 18. Bg5 Be7 19. Bxh4 Nb6 20. Bxf6 Bxf6 21. Qe2 Kf8 22. Be4 a5 23. Qb5 Qa7 24. Nd2 Kg7 25. Nc4 Nxc4 26. Qxc4 Rhb8 27. g4 Bg5 28. Rh1 Qe7 29. Qc6 a4 30. Rh2 Bf4 31. Re2 Qd8 32. Rh1 Ra5 33. Qc4 Rc5 34. Qd3 Qc7 35. h4 a3 36. b3 Rc3 37. Qd1 Rc8 38. g5 Rh8 39. Rg2 Re3 40. c4 bxc3 41. h5 Rxh5 42. Rxh5 gxh5 43. Qh1 c2+ 44. Rxc2 Qa5 0-1

[Event "Oberliga Nord O 1819"]
[Site "Germany"]
[Date "2019.02.03"]
[Round "6.2"]
[White "Thesing, Matthias"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "B10"]
[WhiteElo "2316"]
[BlackElo "2116"]
[PlyCount "69"]
[EventDate "2018.10.21"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]
[WhiteTeam "Kreuzberg"]
[BlackTeam "Berlin Makkabi"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. e4 c6 2. c4 d5 3. exd5 cxd5 4. cxd5 Nf6 5. Nc3 g6 6. Bc4 a6 7. a4 Bg7 8. Nf3 Nbd7 9. 0-0 0-0 10. Re1 Nb6 11. Qb3 Nxc4 12. Qxc4 e6 13. d4 Nxd5 14. Bg5 Qb6 15. Nxd5 exd5 16. Qxd5 Be6 17. Qc5 Qxc5 18. dxc5 Rfc8 19. Be7 Bxb2 20. Rab1 Ba3 21. c6 Bxe7 22. cxb7 Rab8 23. bxc8Q+ Rxc8 24. Nd4 Ba2 25. Rbc1 Rxc1 26. Rxc1 Bf6 27. Nc6 Bb3 28. a5 Kg7 29. Nb8 Bd8 30. Rc5 Kf6 31. Nxa6 Ke6 32. Rc3 Bd5 33. Nc7+ Kd6 34. Nxd5 Bxa5 35. Rd3 1-0

[Event "Oberliga Nord O 1819"]
[Site "Germany"]
[Date "2019.01.20"]
[Round "5.2"]
[White "Dimitrijeski, Boris"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "E34"]
[WhiteElo "2221"]
[BlackElo "2116"]
[PlyCount "104"]
[EventDate "2018.10.21"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]
[WhiteTeam "Koenig Tegel II"]
[BlackTeam "Berlin Makkabi"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 d5 5. cxd5 Qxd5 6. e3 0-0 7. Bd2 Bxc3 8. Bxc3 Bd7 9. Ne2 Nc6 10. Nf4 Qd6 11. Be2 Nb4 12. Qb3 Nbd5 13. Nxd5 Nxd5 14. Bd2 Bc6 15. 0-0 f5 16. Qc4 a6 17. Qb3 Rf6 18. Rfc1 Rh6 19. g3 Rg6 20. Bh5 Rf6 21. Bf3 Raf8 22. Bg2 g5 23. a4 g4 24. Qa3 Qd7 25. Qc5 Bxa4 26. Bxd5 exd5 27. Qxc7 Qxc7 28. Rxc7 Bc6 29. Bb4 Re8 30. Kf1 Rf7 31. Rxf7 Kxf7 32. Ke1 Re6 33. Kd2 Rh6 34. Rh1 Ke8 35. Bc5 Kd7 36. Bf8 Rf6 37. Bg7 Rg6 38. Be5 Rh6 39. Bf4 Rh3 40. Kc3 Bb5 41. Kb4 b6 42. b3 Bc6 43. Be5 Kc8 44. f3 a5+ 45. Kc3 gxf3 46. Rf1 Rxh2 47. Rxf3 Rh5 48. Rf4 Bd7 49. Rh4 Rxh4 50. gxh4 b5 51. h5 b4+ 52. Kb2 Kb7 1/2-1/2

[Event "Oberliga Nord O 1819"]
[Site "Germany"]
[Date "2018.12.16"]
[Round "4.2"]
[White "Krefenstein, Sergej"]
[Black "Waldmann, Hans Joachim"]
[Result "0-1"]
[ECO "A46"]
[WhiteElo "2116"]
[BlackElo "2286"]
[PlyCount "76"]
[EventDate "2018.10.21"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]
[WhiteTeam "Berlin Makkabi"]
[BlackTeam "Berlin Weisse Dame"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. d4 Nf6 2. Nf3 d6 3. h3 c6 4. c4 Nbd7 5. Bf4 g6 6. e3 Bg7 7. Be2 Qa5+ 8. Qd2 Qxd2+ 9. Nbxd2 0-0 10. 0-0 a5 11. Bh2 b6 12. Rfe1 Re8 13. Rad1 Bb7 14. Nb1 Ne4 15. Bd3 Ndf6 16. Nc3 Nxc3 17. bxc3 Ba6 18. Re2 Nd7 19. Rb2 Rec8 20. Rb3 c5 21. Nd2 d5 22. Bf1 cxd4 23. exd4 dxc4 24. Rbb1 b5 25. Re1 Nb6 26. Rxe7 Nd5 27. Rd7 Nxc3 28. Re1 Rd8 29. Ree7 Rxd7 30. Rxd7 Nxa2 31. Ne4 c3 32. Bd3 Nb4 33. Be2 c2 34. Bf4 Re8 35. Nd6 Rxe2 36. Rd8+ Bf8 37. Kf1 Re6 38. Ne8 Nd3 0-1

[Event "Oberliga Nord O 1819"]
[Site "Germany"]
[Date "2018.11.25"]
[Round "3.3"]
[White "Krefenstein, Sergej"]
[Black "Urban, Julian"]
[Result "1/2-1/2"]
[ECO "A48"]
[WhiteElo "2116"]
[BlackElo "2248"]
[PlyCount "138"]
[EventDate "2018.10.21"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]
[WhiteTeam "Berlin Makkabi"]
[BlackTeam "Berlin Empor"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. d4 Nf6 2. Nf3 g6 3. Bf4 Bg7 4. e3 0-0 5. Be2 d6 6. h3 c5 7. Nbd2 cxd4 8. exd4 Nc6 9. c3 Re8 10. Nc4 Be6 11. 0-0 Rc8 12. Ne3 Nd5 13. Nxd5 Bxd5 14. Bg5 Qb6 15. Qd2 a5 16. Ne1 a4 17. Nc2 Na5 18. Ne3 Bc4 19. Rfe1 Bxe2 20. Qxe2 Qc6 21. Rad1 b5 22. Qg4 d5 23. Qh4 Rc7 24. Ng4 Nc4 25. Re2 Nd6 26. Ne5 Bxe5 27. dxe5 Nf5 28. Qf4 Qe6 29. Red2 Rc4 30. Qf3 Qxe5 31. Rxd5 Qe6 32. Rxb5 Nd6 33. Rb6 Re4 34. Bf4 Qxa2 35. Bxd6 exd6 36. Rdxd6 Qc4 37. Qd3 Qc7 38. Rbc6 Qb8 39. Rb6 Qa7 40. Rbc6 Qb8 41. Rb6 Qc7 42. g3 Qc5 43. Rb5 Qc8 44. Kg2 Qa8 45. Qd5 Qxd5 46. Rdxd5 Ra8 47. Rd7 Re6 48. Rbb7 Rf6 49. Ra7 Rxa7 50. Rxa7 Rb6 51. Rxa4 Rxb2 52. Rf4 Kg7 53. h4 h5 54. c4 f6 55. Kf3 g5 56. Rd4 Kg6 57. Ke3 Rc2 58. hxg5 fxg5 59. f3 Rc3+ 60. Ke4 h4 61. gxh4 gxh4 62. Kd5 h3 63. Rg4+ Kf5 64. Rg3 Rd3+ 65. Kc6 Rd4 66. Rxh3 Rxc4+ 67. Kd5 Ra4 68. Rh5+ Kf6 69. Rh1 Kf5 1/2-1/2

[Event "Oberliga Nord O 1819"]
[Site "Germany"]
[Date "2018.11.11"]
[Round "2.2"]
[White "Krefenstein, Sergej"]
[Black "Schoewel, Matthias"]
[Result "1/2-1/2"]
[ECO "D00"]
[WhiteElo "2116"]
[BlackElo "2233"]
[PlyCount "62"]
[EventDate "2018.10.21"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]
[WhiteTeam "Berlin Makkabi"]
[BlackTeam "Oberschoeneweide"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. d4 d5 2. Bf4 e6 3. e3 Bd6 4. Bg3 Nf6 5. Bd3 Nc6 6. Nf3 Bxg3 7. hxg3 Qd6 8. c3 e5 9. dxe5 Nxe5 10. Nxe5 Qxe5 11. Nd2 Bd7 12. Nf3 Qe7 13. Qc2 0-0-0 14. 0-0-0 Kb8 15. Nd4 c5 16. Nf5 Qf8 17. Qe2 g6 18. Nh6 Qe7 19. Qf3 Be6 20. Kb1 Ka8 21. Bc2 Rd6 22. Qf4 Rhd8 23. g4 a6 24. f3 Nd7 25. Nf5 Bxf5 26. gxf5 Nf6 27. g4 R6d7 28. a3 Re8 29. Rhe1 Qd8 30. Ba4 b5 31. Bb3 Qb6 1/2-1/2

[Event "Berlin Lichtenrade op 14th"]
[Site "Berlin"]
[Date "2018.11.04"]
[Round "9"]
[White "Juhnke, Juergen"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "B12"]
[WhiteElo "2228"]
[BlackElo "2116"]
[PlyCount "79"]
[EventDate "2018.10.27"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 187 Extra"]
[Source "ChessBase"]
[SourceDate "2018.11.04"]
[SourceVersion "1"]
[SourceVersionDate "2018.11.04"]
[SourceQuality "1"]

1. e4 c6 2. d4 d5 3. e5 Bf5 4. h4 h6 5. g4 Bh7 6. e6 fxe6 7. Bd3 e5 8. dxe5 Qc7 9. f4 Bxd3 10. Qxd3 e6 11. Nf3 Na6 12. Nd4 Nc5 13. Qe3 Qd7 14. h5 Ne4 15. Nd2 0-0-0 16. N4b3 Nxd2 17. Bxd2 d4 18. Qe4 Qd5 19. Qxd5 Rxd5 20. 0-0-0 b6 21. c4 dxc3 22. Bxc3 Ne7 23. Nd4 Kd7 24. f5 exf5 25. gxf5 Rg8 26. Rhg1 Ke8 27. f6 gxf6 28. exf6 Rxg1 29. Rxg1 Nc8 30. Nxc6 Rxh5 31. Re1+ Kd7 32. Ne5+ Ke6 33. Ng6+ Kf7 34. Nh8+ Kg8 35. f7+ Kh7 36. Re8 Ne7 37. Rxf8 Ng6 38. Rg8 Rf5 39. Rg7+ Kxh8 40. Rxg6+ 1-0

[Event "Berlin Lichtenrade op 14th"]
[Site "Berlin"]
[Date "2018.11.03"]
[Round "8"]
[White "Krefenstein, Sergej"]
[Black "Niehaus, Frank"]
[Result "1-0"]
[ECO "A80"]
[WhiteElo "2116"]
[BlackElo "2195"]
[PlyCount "107"]
[EventDate "2018.10.27"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 187 Extra"]
[Source "ChessBase"]
[SourceDate "2018.11.04"]
[SourceVersion "1"]
[SourceVersionDate "2018.11.04"]
[SourceQuality "1"]

1. d4 d5 2. Bf4 e6 3. e3 f5 4. Bd3 Nf6 5. Nf3 Be7 6. 0-0 0-0 7. h3 c6 8. c4 Ne4 9. Ne5 Nd7 10. Nd2 Ndf6 11. Ndf3 Qe8 12. Bh2 Kh8 13. c5 Rg8 14. Ne1 b6 15. b4 a5 16. cxb6 axb4 17. Qc2 Bb7 18. Be2 Rf8 19. N1d3 Ra3 20. Rfc1 Qa8 21. Qb2 Nc3 22. Nf4 Qa5 23. Nxe6 Rc8 24. Nf7+ Kg8 25. Nd6 Bxd6 26. Bxd6 Qxb6 27. Rxc3 Rxc3 28. Bxb4 Rc4 29. Bxc4 dxc4 30. Nc5 Rb8 31. a3 Ba6 32. Qc2 g6 33. Nxa6 Qxa6 34. Rc1 Nd5 35. Qxc4 Qxc4 36. Rxc4 Rc8 37. Kf1 Kf7 38. Ke2 Ke6 39. Bd2 Kd7 40. Ra4 Rc7 41. Kd3 Rb7 42. Bb4 Kc7 43. f3 Kd7 44. g3 Nf6 45. Ra8 Ke6 46. Rc8 Kd7 47. Rh8 Ke6 48. Rc8 Kd7 49. Rf8 Ke6 50. Rd8 Nd7 51. Rc8 Rb6 52. Rc7 Ra6 53. e4 fxe4+ 54. fxe4 1-0

[Event "Berlin Lichtenrade op 14th"]
[Site "Berlin"]
[Date "2018.11.02"]
[Round "7"]
[White "Krefenstein, Sergej"]
[Black "Jaeger, Andre"]
[Result "1-0"]
[ECO "A48"]
[WhiteElo "2116"]
[BlackElo "1919"]
[PlyCount "115"]
[EventDate "2018.10.27"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 187 Extra"]
[Source "ChessBase"]
[SourceDate "2018.11.04"]
[SourceVersion "1"]
[SourceVersionDate "2018.11.04"]
[SourceQuality "1"]

1. d4 Nf6 2. Nf3 g6 3. Bf4 Bg7 4. e3 0-0 5. h3 c5 6. Nbd2 cxd4 7. exd4 b6 8. Be2 Bb7 9. 0-0 Nc6 10. c3 d6 11. Bh2 Re8 12. Nc4 d5 13. Nce5 Ne4 14. Bb5 Rc8 15. Qa4 Bxe5 16. Nxe5 Nxe5 17. Bxe8 Nc4 18. Qd7 Qxd7 19. Bxd7 Rd8 20. Bb5 a6 21. Bxc4 dxc4 22. Rfe1 Rd7 23. Be5 f6 24. Bf4 f5 25. Be5 Kf7 26. h4 h5 27. f3 Nf6 28. Bxf6 Kxf6 29. Kf2 a5 30. Kg3 Bd5 31. Kf4 e6 32. Re2 Rc7 33. Rg1 Rd7 34. g3 Rc7 35. Rh2 Rf7 36. Ke3 Ke7 37. Rf1 Rf8 38. Rhf2 Rf7 39. Kf4 Kf6 40. g4 Rh7 41. Rh2 Rh8 42. Rg1 Rh7 43. gxh5 Rxh5 44. Rg5 Rh7 45. h5 Rxh5 46. Rhxh5 gxh5 47. Rxh5 Kg7 48. Rh3 b5 49. Ke5 b4 50. f4 b3 51. axb3 cxb3 52. Rg3+ Kf7 53. Rg1 a4 54. Ra1 Bc6 55. Kd6 Bb5 56. Kc5 Be8 57. c4 Kf6 58. Kd6 1-0

[Event "Berlin Lichtenrade op 14th"]
[Site "Berlin"]
[Date "2018.11.01"]
[Round "6"]
[White "Biriukov, Nikolai"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "D10"]
[WhiteElo "2363"]
[BlackElo "2116"]
[PlyCount "79"]
[EventDate "2018.10.27"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 187 Extra"]
[Source "ChessBase"]
[SourceDate "2018.11.04"]
[SourceVersion "1"]
[SourceVersionDate "2018.11.04"]
[SourceQuality "1"]

1. d4 d5 2. c4 c6 3. Nc3 Nf6 4. e3 Bg4 5. f3 Bf5 6. cxd5 Nxd5 7. e4 Nxc3 8. bxc3 Bg6 9. Rb1 b6 10. Bd3 e6 11. f4 Bd6 12. Nh3 f6 13. 0-0 0-0 14. Qb3 Kh8 15. Rb2 Qe7 16. Re2 Nd7 17. f5 Bf7 18. fxe6 Bxe6 19. Qc2 Bg8 20. Nf4 Rfe8 21. Rf3 Bxf4 22. Bxf4 c5 23. Ba6 Nf8 24. e5 Ng6 25. Bb5 Rf8 26. exf6 Qxf6 27. Be5 Qg5 28. Rg3 Qh5 29. Bd3 Nxe5 30. dxe5 Be6 31. h3 Qh4 32. Rge3 Rad8 33. Re4 Qh5 34. Bc4 Bf5 35. e6 Bxe4 36. Qxe4 Rfe8 37. e7 Rd1+ 38. Kh2 Rd7 39. Rf2 g6 40. Rf8+ 1-0

[Event "Berlin Lichtenrade op 14th"]
[Site "Berlin"]
[Date "2018.10.31"]
[Round "5"]
[White "Zhou, Lepu Coco"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "B11"]
[WhiteElo "1617"]
[BlackElo "2116"]
[PlyCount "120"]
[EventDate "2018.10.27"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 187 Extra"]
[Source "ChessBase"]
[SourceDate "2018.11.04"]
[SourceVersion "1"]
[SourceVersionDate "2018.11.04"]
[SourceQuality "1"]

1. e4 c6 2. Nc3 d5 3. Nf3 Nf6 4. e5 Ne4 5. d4 Nxc3 6. bxc3 c5 7. Bd3 c4 8. Be2 h6 9. 0-0 Bf5 10. Nh4 Be4 11. e6 fxe6 12. Bh5+ Kd7 13. Bg6 Bxg6 14. Nxg6 Rg8 15. Ne5+ Kc8 16. Qg4 Qd6 17. Ba3 Qa6 18. Qg6 Kd8 19. Qf7 Qxa3 20. Qxg8 Nd7 21. Qxe6 Nxe5 22. Qxe5 Qd6 23. Qxd6+ exd6 24. Rfe1 Kd7 25. Rab1 b6 26. f4 Be7 27. g3 Bf6 28. Kg2 Kc6 29. Re6 b5 30. a4 a6 31. Ree1 Rb8 32. Rb2 a5 33. axb5+ Rxb5 34. Reb1 Rxb2 35. Rxb2 a4 36. Rb4 Bd8 37. Rxa4 Kb5 38. Rb4+ Kc6 39. Rb8 Ba5 40. Rc8+ Kb5 41. Rg8 Bxc3 42. Rxg7 Bxd4 43. Rg6 Bc5 44. Rxh6 d4 45. Re6 Kb4 46. Kf3 Kc3 47. Re2 d3 48. cxd3 Kxd3 49. Re1 Kd2 50. Ra1 Bd4 51. Ra5 Kd3 52. Ra2 c3 53. Kg4 c2 54. Rxc2 Kxc2 55. Kf5 Kd3 56. Ke6 Ke4 57. Kxd6 Kf5 58. h3 Bf2 59. g4+ Kxf4 60. Kd5 Bh4 1/2-1/2

[Event "Berlin Lichtenrade op 14th"]
[Site "Berlin"]
[Date "2018.10.30"]
[Round "4"]
[White "Krefenstein, Sergej"]
[Black "Fahland, Maximilian"]
[Result "1-0"]
[ECO "D00"]
[WhiteElo "2116"]
[BlackElo "1941"]
[PlyCount "61"]
[EventDate "2018.10.27"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 187 Extra"]
[Source "ChessBase"]
[SourceDate "2018.11.04"]
[SourceVersion "1"]
[SourceVersionDate "2018.11.04"]
[SourceQuality "1"]

1. d4 Nf6 2. Bf4 d5 3. e3 Bf5 4. c4 e6 5. Qb3 Qc8 6. Nc3 c6 7. Nf3 h6 8. Rc1 dxc4 9. Bxc4 Be7 10. h3 0-0 11. 0-0 Nbd7 12. Rfe1 Ne4 13. Nxe4 Bxe4 14. Nd2 Bh7 15. e4 Nb6 16. Bf1 Qd7 17. Nf3 Rfd8 18. a4 Bf6 19. a5 Nc8 20. a6 b6 21. d5 exd5 22. exd5 Qxd5 23. Rcd1 Bd3 24. Qxd5 cxd5 25. Bxd3 Nd6 26. Be5 Bxe5 27. Rxe5 Ne8 28. Rc1 Kf8 29. Nd4 Nf6 30. Rc7 Rdc8 31. Ree7 1-0

[Event "Berlin Lichtenrade op 14th"]
[Site "Berlin"]
[Date "2018.10.29"]
[Round "3"]
[White "Florstedt, Johannes"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "B12"]
[WhiteElo "2310"]
[BlackElo "2116"]
[PlyCount "55"]
[EventDate "2018.10.27"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 187 Extra"]
[Source "ChessBase"]
[SourceDate "2018.11.04"]
[SourceVersion "1"]
[SourceVersionDate "2018.11.04"]
[SourceQuality "1"]

1. e4 c6 2. d4 d5 3. e5 Bf5 4. h4 h5 5. Bd3 Bxd3 6. Qxd3 e6 7. Bg5 Be7 8. Nf3 Nh6 9. Nc3 Nf5 10. Ne2 Qa5+ 11. c3 Qa6 12. Qd2 Nd7 13. Bxe7 Nxe7 14. 0-0 Nf5 15. Ng3 0-0-0 16. Nxf5 exf5 17. Qf4 Qb6 18. Ng5 Rdf8 19. Qxf5 g6 20. Qh3 f5 21. exf6 Rxf6 22. Rae1 Rf5 23. Re6 Qxb2 24. Qg3 Rf6 25. Rxf6 Nxf6 26. Qe5 Rf8 27. Qd6 Nd7 28. Ne6 1-0

[Event "Oberliga Nord O 1819"]
[Site "Germany"]
[Date "2018.10.21"]
[Round "1.2"]
[White "De Wiljes, Jan Hendrik"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "D02"]
[WhiteElo "2336"]
[BlackElo "2116"]
[PlyCount "143"]
[EventDate "2018.10.21"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]
[WhiteTeam "Berlin SF III"]
[BlackTeam "Berlin Makkabi"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. d4 d5 2. Bf4 Nf6 3. e3 c5 4. c3 Nc6 5. Nd2 cxd4 6. exd4 g6 7. h3 Bg7 8. Ngf3 0-0 9. Be2 Nd7 10. 0-0 e5 11. dxe5 Ndxe5 12. Nxe5 Nxe5 13. Be3 Be6 14. Bc5 Re8 15. Bb5 Bd7 16. Bxd7 Qxd7 17. Be3 Nc6 18. Nf3 Re4 19. Qd3 Rd8 20. Rfd1 Qe7 21. Bg5 Bf6 22. Bxf6 Qxf6 23. Rd2 Ne5 24. Nxe5 Qxe5 25. Rad1 Kg7 26. g3 h5 27. h4 Rd6 28. Kg2 Rb6 29. Qc2 Rb5 30. Rd4 Rc5 31. Qd3 Ra5 32. Rxd5 Rxd5 33. Qxd5 Qe7 34. Qd7 Qf6 35. Qxb7 Re2 36. Qxa7 Qc6+ 37. Kg1 Rxb2 38. Qd4+ Kg8 39. Qe5 Qb6 40. Qd4 Qxd4 41. cxd4 Rxa2 42. Rd3 Kf8 43. Kg2 Ke7 44. Kf3 Ke6 45. Re3+ Kd6 46. Re2 Ra3+ 47. Ke4 Rb3 48. Ra2 Rb6 49. Ra7 Ke6 50. Ra2 Kd6 51. f3 Ke6 52. Ra7 Kf6 53. Rc7 Re6+ 54. Kf4 Rd6 55. Rc4 Ke6 56. Kg5 Rd5+ 57. Kh6 Rf5 58. f4 Rd5 59. Kg7 Rd7 60. Rc5 Ra7 61. Re5+ Kd6 62. Kf6 Ra3 63. Rg5 Ra7 64. f5 gxf5 65. Rxh5 f4 66. gxf4 Ra4 67. Kxf7 Rxd4 68. Rf5 Rd1 69. h5 Rh1 70. Kg7 Ke6 71. Re5+ Kd7 72. h6 1-0

[Event "Berlin Lichtenberger op 17th"]
[Site "Berlin"]
[Date "2018.08.25"]
[Round "8"]
[White "Krefenstein, Sergej"]
[Black "Joppien, Arne"]
[Result "0-1"]
[ECO "A13"]
[WhiteElo "2120"]
[BlackElo "1921"]
[PlyCount "92"]
[EventDate "2018.08.18"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 186 Extra"]
[Source "ChessBase"]
[SourceDate "2018.08.24"]
[SourceVersion "1"]
[SourceVersionDate "2018.08.24"]
[SourceQuality "1"]

1. Nf3 d5 2. c4 e6 3. g3 c6 4. Bg2 Nf6 5. b3 d4 6. 0-0 c5 7. d3 Nc6 8. e3 Be7 9. exd4 cxd4 10. Re1 0-0 11. Bb2 Rb8 12. Na3 Bxa3 13. Bxa3 Re8 14. b4 b5 15. Nd2 Bd7 16. cxb5 Rxb5 17. Nc4 Qb8 18. Bb2 Rd8 19. a4 Rxb4 20. Ba3 Rb7 21. Nd6 Rb3 22. Nb5 Rxb5 23. axb5 Qxb5 24. Qc2 a5 25. Reb1 Nb4 26. Bxb4 axb4 27. Rb3 Rc8 28. Qb1 Nd5 29. Ra7 g6 30. h4 e5 31. Qa1 Nc3 32. Rb7 Qxd3 33. Rxd7 Ne2+ 34. Kh2 Qxb3 35. Qa6 Qc2 36. Qf6 Qf5 37. Qe7 b3 38. f4 Nxf4 39. g4 Qe6 40. Rd8+ Rxd8 41. Qxd8+ Kg7 42. g5 Nxg2 43. Kxg2 Qg4+ 44. Kf1 Qf4+ 45. Kg2 b2 46. h5 gxh5 0-1

[Event "Berlin Lichtenberger op 17th"]
[Site "Berlin"]
[Date "2018.08.24"]
[Round "7"]
[White "Kapr, Klaus"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "B14"]
[WhiteElo "1999"]
[BlackElo "2120"]
[PlyCount "82"]
[EventDate "2018.08.18"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 186 Extra"]
[Source "ChessBase"]
[SourceDate "2018.08.24"]
[SourceVersion "1"]
[SourceVersionDate "2018.08.24"]
[SourceQuality "1"]

1. e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. Nc3 e6 6. Nf3 Bb4 7. Qb3 Nc6 8. cxd5 Nxd5 9. Bb5 0-0 10. 0-0 Nce7 11. Bg5 Qa5 12. Rac1 a6 13. Bd3 h6 14. Bh4 Nc6 15. Bb1 Bd7 16. a3 Bd6 17. Qc2 f5 18. Bg3 Bxg3 19. hxg3 Nxc3 20. Qxc3 Qxc3 21. Rxc3 Rad8 22. Rd1 Bc8 23. Ba2 Rd6 24. Rcd3 Rfd8 25. Rc1 Kf7 26. Rdc3 Kf6 27. Kf1 g5 28. g4 fxg4 29. Ne5 Bd7 30. Nxg4+ Kg7 31. Ne5 Be8 32. Rb3 b5 33. Nxc6 Bxc6 34. Rbc3 Be4 35. f3 Bg6 36. Rc6 Kf6 37. d5 e5 38. Rxd6+ Rxd6 39. Rc7 h5 40. Kf2 e4 41. Bb1 e3+ 0-1

[Event "Berlin Lichtenberger op 17th"]
[Site "Berlin"]
[Date "2018.08.23"]
[Round "6"]
[White "Krefenstein, Sergej"]
[Black "Polatel, Ali"]
[Result "0-1"]
[ECO "A11"]
[WhiteElo "2120"]
[BlackElo "2230"]
[PlyCount "176"]
[EventDate "2018.08.18"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 186 Extra"]
[Source "ChessBase"]
[SourceDate "2018.08.24"]
[SourceVersion "1"]
[SourceVersionDate "2018.08.24"]
[SourceQuality "1"]

1. Nf3 d5 2. c4 c6 3. g3 Nf6 4. Bg2 g6 5. b3 Bg7 6. Bb2 0-0 7. 0-0 a5 8. d3 Bg4 9. Nbd2 Nbd7 10. h3 Bxf3 11. Nxf3 e6 12. Qc2 Qe7 13. Rac1 Rfd8 14. Rfd1 Ne8 15. Bxg7 Kxg7 16. d4 Ndf6 17. c5 Nc7 18. Ne5 Nd7 19. Nxd7 Rxd7 20. Qc3 Rdd8 21. h4 Qf6 22. Qe3 Nb5 23. a4 Nc7 24. Qe5 Qxe5 25. dxe5 Na6 26. e3 Nb4 27. Rd4 f6 28. exf6+ Kxf6 29. Rcd1 e5 30. R4d2 Na6 31. Rc1 Re8 32. Bf1 Nb4 33. Rcd1 e4 34. Kg2 h6 35. Be2 Re7 36. Rh1 Ke5 37. Rc1 Rf8 38. Bf1 g5 39. h5 Ref7 40. g4 Rb8 41. Rc3 Na6 42. Rcc2 Nc7 43. Rc1 Ne6 44. Rb2 b6 45. cxb6 Rxb6 46. Rc3 Rfb7 47. Rbc2 Kd6 48. Be2 Nd8 49. Bd1 Rb4 50. Rc1 R4b6 51. R1c2 Rb4 52. Rc1 R7b6 53. Rc5 Nb7 54. R5c3 c5 55. Kf1 Ke5 56. Rxc5 Nxc5 57. Rxc5 Ra6 58. Be2 Kd6 59. Rc8 Rc6 60. Rd8+ Kc5 61. Ra8 Rxb3 62. Rxa5+ Kd6 63. Ra8 Rb1+ 64. Kg2 Rb2 65. Bb5 Rcc2 66. Rf8 Ke7 67. Rf5 Ke6 68. Be8 d4 69. exd4 Re2 70. Bb5 Re1 71. Re5+ Kd6 72. a5 Rbb1 73. f3 exf3+ 74. Kxf3 Rxe5 75. dxe5+ Kxe5 76. Be2 Rb3+ 77. Kf2 Kf4 78. a6 Rb2 79. Kf1 Ke3 80. Bc4 Rb4 81. Bd5 Rf4+ 82. Kg2 Rxg4+ 83. Kh3 Ra4 84. Bb7 Kf4 85. Bc8 Ra3+ 86. Kg2 g4 87. Bb7 Ra2+ 88. Kg1 Kg5 0-1

[Event "Berlin Lichtenberger op 17th"]
[Site "Berlin"]
[Date "2018.08.22"]
[Round "5"]
[White "Jaeger, Andre"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "E20"]
[WhiteElo "1974"]
[BlackElo "2120"]
[PlyCount "44"]
[EventDate "2018.08.18"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 186 Extra"]
[Source "ChessBase"]
[SourceDate "2018.08.24"]
[SourceVersion "1"]
[SourceVersionDate "2018.08.24"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. f3 c5 5. d5 d6 6. e4 b5 7. dxe6 Bxe6 8. cxb5 0-0 9. Bg5 h6 10. Bh4 g5 11. Bf2 d5 12. a3 Bxc3+ 13. bxc3 Qa5 14. Qd2 Nbd7 15. Bd3 dxe4 16. Bxe4 Nxe4 17. fxe4 Nf6 18. Bxc5 Nxe4 19. Bb4 Nxd2 20. Bxa5 Nb3 21. Bb4 Nxa1 22. Bxf8 Kxf8 0-1

[Event "Berlin Lichtenberger op 17th"]
[Site "Berlin"]
[Date "2018.08.21"]
[Round "4"]
[White "Krefenstein, Sergej"]
[Black "Hacker, Jonas"]
[Result "0-1"]
[ECO "A09"]
[WhiteElo "2120"]
[BlackElo "2316"]
[PlyCount "48"]
[EventDate "2018.08.18"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 186 Extra"]
[Source "ChessBase"]
[SourceDate "2018.08.24"]
[SourceVersion "1"]
[SourceVersionDate "2018.08.24"]
[SourceQuality "1"]

1. Nf3 d5 2. c4 d4 3. b4 g5 4. Bb2 Bg7 5. e3 e5 6. exd4 exd4 7. Bd3 g4 8. Qe2+ Kf8 9. Ne5 f6 10. Nxg4 h5 11. Ne3 dxe3 12. dxe3 Nc6 13. b5 Ne5 14. Bc2 f5 15. Nc3 Be6 16. Nd5 c6 17. bxc6 bxc6 18. Bxe5 Bxe5 19. Nf4 Qa5+ 20. Kf1 Bxf4 21. exf4 Qc3 22. Qxe6 Qxa1+ 23. Ke2 Qf6 24. Qd7 Qe7+ 0-1

[Event "Berlin Lichtenberger op 17th"]
[Site "Berlin"]
[Date "2018.08.20"]
[Round "3"]
[White "Baranowsky, Peter"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "B13"]
[WhiteElo "1848"]
[BlackElo "2120"]
[PlyCount "52"]
[EventDate "2018.08.18"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 186 Extra"]
[Source "ChessBase"]
[SourceDate "2018.08.24"]
[SourceVersion "1"]
[SourceVersionDate "2018.08.24"]
[SourceQuality "1"]

1. e4 c6 2. d4 d5 3. exd5 cxd5 4. Bd3 Nc6 5. c3 Qc7 6. h3 g6 7. Qf3 Nxd4 8. Qxd5 Bg7 9. cxd4 Qxc1+ 10. Ke2 Nf6 11. Qb3 0-0 12. Qc2 Qg5 13. Nd2 Nd5 14. Ne4 Nf4+ 15. Kd2 Qxg2 16. Ne2 Qf3 17. Raf1 Bh6 18. Nxf4 Bxf4+ 19. Ke1 f5 20. Bc4+ Kg7 21. Nd2 Qc6 22. Qc3 Bd7 23. Nf3 Rac8 24. d5+ Qf6 25. Qxf6+ exf6 26. b3 b5 0-1

[Event "Berlin Lichtenberger op 17th"]
[Site "Berlin"]
[Date "2018.08.19"]
[Round "2"]
[White "Krefenstein, Sergej"]
[Black "Matitschka, Heinz"]
[Result "1-0"]
[ECO "A14"]
[WhiteElo "2120"]
[BlackElo "1938"]
[PlyCount "81"]
[EventDate "2018.08.18"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 186 Extra"]
[Source "ChessBase"]
[SourceDate "2018.08.24"]
[SourceVersion "1"]
[SourceVersionDate "2018.08.24"]
[SourceQuality "1"]

1. Nf3 Nf6 2. g3 e6 3. Bg2 d5 4. b3 Be7 5. Bb2 Nbd7 6. 0-0 c6 7. d3 Qc7 8. c4 0-0 9. Nc3 Re8 10. Rc1 Qa5 11. Rc2 Nc5 12. Qd2 Qb4 13. Rb1 a5 14. Ba1 Qb6 15. Rcc1 Bf8 16. Nd1 Ncd7 17. Qf4 Ba3 18. Rc2 Be7 19. g4 Nf8 20. Ne5 Ng6 21. Nxg6 hxg6 22. e4 dxc4 23. dxc4 e5 24. Bxe5 Bxg4 25. Ne3 Be6 26. Bf3 Qb4 27. Bc3 Qa3 28. Kg2 Rad8 29. Qc7 a4 30. Qxb7 axb3 31. Rxb3 Qc5 32. e5 Nh5 33. Qxc6 Nf4+ 34. Kg3 Nh5+ 35. Kg2 Nf4+ 36. Kg3 Nh5+ 37. Kg2 Nf4+ 38. Kg1 Nh3+ 39. Kf1 Bxc4+ 40. Nxc4 Rd1+ 41. Be1 1-0

[Event "Berlin Lichtenberger op 17th"]
[Site "Berlin"]
[Date "2018.08.18"]
[Round "1"]
[White "Schulz Runge, Michael"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "A22"]
[WhiteElo "1758"]
[BlackElo "2120"]
[PlyCount "84"]
[EventDate "2018.08.18"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 186 Extra"]
[Source "ChessBase"]
[SourceDate "2018.08.24"]
[SourceVersion "1"]
[SourceVersionDate "2018.08.24"]
[SourceQuality "1"]

1. c4 e5 2. Nc3 Bb4 3. g3 Nf6 4. Bg2 0-0 5. e3 Bxc3 6. dxc3 e4 7. Ne2 d6 8. 0-0 Nc6 9. b3 Re8 10. Qc2 Bg4 11. Nd4 Ne5 12. h3 Bh5 13. Ne2 g5 14. Ba3 b6 15. c5 bxc5 16. c4 Qe7 17. Kh1 Qe6 18. Ng1 Bf3 19. Rab1 Bxg2+ 20. Kxg2 Nd3 21. Bb2 Nxb2 22. Qxb2 Nd7 23. Rbd1 Ne5 24. Qe2 Qg6 25. Rd5 a5 26. Rd2 a4 27. Rb2 Nd3 28. Rbb1 axb3 29. Rxb3 Qe6 30. Qh5 Qg6 31. Qe2 Reb8 32. Rfb1 Rxb3 33. Rxb3 Nc1 34. Qc2 Nxb3 35. Qxb3 Qf6 36. a4 h6 37. Qb5 Qa1 38. Qc6 Rxa4 39. Qe8+ Kg7 40. Qxe4 Ra2 41. Qd3 Qe1 42. Qf5 Ra1 0-1

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2018.07.08"]
[Round "9"]
[White "Krefenstein, Sergej"]
[Black "Kather, Yannick"]
[Result "0-1"]
[ECO "D85"]
[WhiteElo "2119"]
[BlackElo "2053"]
[PlyCount "120"]
[EventDate "2018.06.30"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 185 Extra"]
[Source "ChessBase"]
[SourceDate "2018.07.29"]
[SourceVersion "1"]
[SourceVersionDate "2018.07.29"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3 Bg7 7. Nf3 c5 8. Be3 Nc6 9. Qd2 Qa5 10. Rb1 a6 11. Rc1 0-0 12. d5 Rd8 13. c4 Nb4 14. a3 Qxa3 15. Bxc5 Nc2+ 16. Qxc2 Qxc5 17. Bd3 a5 18. 0-0 Bg4 19. Nd2 a4 20. Rb1 Qa7 21. h3 Bd7 22. Nf3 Rac8 23. Qa2 Rc5 24. Qa3 b5 25. Rfc1 bxc4 26. Rxc4 Rdc8 27. Rbc1 Rxc4 28. Rxc4 Rb8 29. Bc2 Qa6 30. Rc7 Be8 31. e5 Rc8 32. Bd3 Qa8 33. Rxc8 Qxc8 34. Bb1 e6 35. Ba2 exd5 36. Bxd5 Bf8 37. Qa2 Qc1+ 38. Kh2 Qa3 39. Qd2 Qe7 40. Qf4 Bg7 41. Qe4 a3 42. Ba2 Qc7 43. Bd5 Bc6 44. Bxc6 a2 45. Qa4 Bxe5+ 46. Nxe5 Qxe5+ 47. f4 Qb2 48. Bd5 a1Q 49. Qe8+ Kg7 50. Qxf7+ Kh6 51. Qf8+ Qg7 52. Qe8 Qad4 53. Be4 Qe3 54. Qd8 Qxf4+ 55. g3 Qxe4 56. Qd2+ g5 57. Qd6+ Qeg6 58. Qd2 Qe6 59. h4 Qge7 60. g4 Qe2+ 0-1

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2018.07.07"]
[Round "8"]
[White "Von Herman, Ulf"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "A36"]
[WhiteElo "2354"]
[BlackElo "2119"]
[PlyCount "17"]
[EventDate "2018.06.30"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 185 Extra"]
[Source "ChessBase"]
[SourceDate "2018.07.29"]
[SourceVersion "1"]
[SourceVersionDate "2018.07.29"]
[SourceQuality "1"]

1. c4 Nf6 2. Nc3 g6 3. g3 Bg7 4. Bg2 0-0 5. e4 d6 6. Nge2 c5 7. 0-0 Nc6 8. d3 Bd7 9. a3 1/2-1/2

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2018.07.06"]
[Round "7"]
[White "Federau, Juergen"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "E60"]
[WhiteElo "2127"]
[BlackElo "2119"]
[PlyCount "83"]
[EventDate "2018.06.30"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 185 Extra"]
[Source "ChessBase"]
[SourceDate "2018.07.29"]
[SourceVersion "1"]
[SourceVersionDate "2018.07.29"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 g6 3. g3 Bg7 4. Bg2 0-0 5. e4 d6 6. Ne2 c5 7. 0-0 Nc6 8. d5 Na5 9. Nd2 a6 10. Rb1 Nd7 11. b3 b5 12. Bb2 Bxb2 13. Rxb2 Rb8 14. Qc2 bxc4 15. bxc4 Rxb2 16. Qxb2 Nb6 17. Qc3 Na4 18. Qc2 Bd7 19. Nf4 Qc7 20. Nd3 Nb6 21. f4 f6 22. f5 g5 23. h4 h6 24. Qc3 Na4 25. Qc2 Kg7 26. Bf3 Be8 27. Kf2 Nb7 28. Rh1 Qa5 29. Nb1 Rh8 30. Ke3 Nb6 31. Nd2 Qa4 32. Qxa4 Nxa4 33. Rb1 Na5 34. Nf2 Bd7 35. Kd3 Rc8 36. Bd1 Rc7 37. Bxa4 Bxa4 38. Rb6 Ra7 39. Kc3 Nb7 40. Nb3 Be8 41. Nd2 Ba4 42. Nb3 1/2-1/2

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2018.07.05"]
[Round "6"]
[White "Krefenstein, Sergej"]
[Black "Rehberg, Raphael"]
[Result "1-0"]
[ECO "E01"]
[WhiteElo "2119"]
[BlackElo "2279"]
[PlyCount "81"]
[EventDate "2018.06.30"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 185 Extra"]
[Source "ChessBase"]
[SourceDate "2018.07.29"]
[SourceVersion "1"]
[SourceVersionDate "2018.07.29"]
[SourceQuality "1"]

1. d4 d5 2. c4 e6 3. Nc3 c6 4. Nf3 dxc4 5. a4 Bb4 6. g3 Nd7 7. Bg2 Ngf6 8. 0-0 0-0 9. Qc2 Qe7 10. Na2 Bd6 11. Qxc4 c5 12. Nc3 Nb6 13. Qb3 cxd4 14. Nxd4 e5 15. Ndb5 Be6 16. Qc2 Bc5 17. Bg5 a6 18. Na3 Rac8 19. a5 Nc4 20. Nxc4 Bxc4 21. Bxf6 gxf6 22. Qe4 Qe6 23. Qh4 f5 24. Bh3 Qg6 25. Rfd1 Rc7 26. e4 fxe4 27. Qxe4 Qxe4 28. Nxe4 Bd4 29. Rac1 Bxb2 30. Rc2 Bb3 31. Rxc7 Bxd1 32. Rxb7 Bd4 33. Bg2 Rc8 34. h3 Be2 35. Nd6 Rc5 36. Nxf7 Rxa5 37. Nh6+ Kf8 38. Bc6 Bc4 39. Rxh7 Ra2 40. Ng4 Bf7 41. Rxf7+ 1-0

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2018.07.04"]
[Round "5"]
[White "Jaeger, Andre"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "E63"]
[WhiteElo "1922"]
[BlackElo "2119"]
[PlyCount "77"]
[EventDate "2018.06.30"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 185 Extra"]
[Source "ChessBase"]
[SourceDate "2018.07.29"]
[SourceVersion "1"]
[SourceVersionDate "2018.07.29"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 g6 3. g3 Bg7 4. Bg2 d6 5. Nc3 0-0 6. Nf3 Nc6 7. 0-0 a6 8. d5 Na5 9. b3 c5 10. dxc6 Nxc6 11. Bb2 Bd7 12. Qd2 Qa5 13. Nd5 Qxd2 14. Nxd2 Nxd5 15. Bxg7 Kxg7 16. cxd5 Nd4 17. e3 Ne2+ 18. Kh1 Rac8 19. Rfe1 Rc2 20. Nc4 Nc3 21. Nb6 Bb5 22. a4 Bd3 23. Rec1 Ne4 24. Rxc2 Bxc2 25. Rc1 Bd3 26. f3 Nf6 27. Rc7 Re8 28. Kg1 e6 29. dxe6 Rxe6 30. Kf2 d5 31. Rxb7 Rc6 32. g4 Rc2+ 33. Kg3 Re2 34. Bf1 Rxe3 35. Bxd3 Rxd3 36. Nd7 Nxd7 37. Rxd7 Rxb3 38. Rxd5 Rb6 39. g5 1/2-1/2

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2018.07.03"]
[Round "4"]
[White "Krefenstein, Sergej"]
[Black "Gelman, Josef"]
[Result "1/2-1/2"]
[ECO "A07"]
[WhiteElo "2119"]
[BlackElo "1989"]
[PlyCount "90"]
[EventDate "2018.06.30"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 185 Extra"]
[Source "ChessBase"]
[SourceDate "2018.07.29"]
[SourceVersion "1"]
[SourceVersionDate "2018.07.29"]
[SourceQuality "1"]

1. Nf3 Nf6 2. g3 g6 3. Bg2 Bg7 4. 0-0 0-0 5. d3 d5 6. Nbd2 Nc6 7. c3 e5 8. Qc2 Qe7 9. e4 dxe4 10. dxe4 Bd7 11. a4 a5 12. b3 Rfd8 13. Nc4 Nh5 14. Ne3 Be6 15. Ba3 Qd7 16. Rad1 Qe8 17. Ng5 Rxd1 18. Rxd1 Rd8 19. Nxe6 Rxd1+ 20. Qxd1 fxe6 21. Bh3 Nf6 22. Qd3 Kf7 23. Qc4 Qd7 24. Kf1 Nd8 25. Ke2 Bh6 26. f3 Nc6 27. Qc5 b6 28. Qb5 Bxe3 29. Kxe3 Qd1 30. Bf1 Qe1+ 31. Be2 Qxc3+ 32. Qd3 Qa1 33. Qc4 Qxa3 34. Qxc6 Qc5+ 35. Qxc5 bxc5 36. Kd3 Nd7 37. Kc4 c6 38. f4 Kf6 39. Bf1 Ke7 40. fxe5 Kf7 41. Be2 Ke7 42. h3 Kf7 43. h4 h6 44. h5 g5 45. Bd1 Ke7 1/2-1/2

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2018.07.02"]
[Round "3"]
[White "Weber, Erwin"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "A48"]
[WhiteElo "1982"]
[BlackElo "2119"]
[PlyCount "39"]
[EventDate "2018.06.30"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 185 Extra"]
[Source "ChessBase"]
[SourceDate "2018.07.29"]
[SourceVersion "1"]
[SourceVersionDate "2018.07.29"]
[SourceQuality "1"]

1. d4 Nf6 2. Nf3 g6 3. Bg5 Bg7 4. Nbd2 0-0 5. e3 d6 6. Bc4 Nbd7 7. 0-0 h6 8. Bh4 Qe8 9. c3 e5 10. dxe5 dxe5 11. e4 Nh5 12. Bg3 Nb6 13. Bb3 Bg4 14. Qc2 Qe7 15. a4 a5 16. Rfe1 Nf4 17. Bxf4 exf4 18. h3 Bd7 19. Nc4 Nxc4 20. Bxc4 1/2-1/2

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2018.07.01"]
[Round "2"]
[White "Krefenstein, Sergej"]
[Black "Hiller, Bernd"]
[Result "1-0"]
[ECO "D08"]
[WhiteElo "2119"]
[BlackElo "1847"]
[PlyCount "55"]
[EventDate "2018.06.30"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 185 Extra"]
[Source "ChessBase"]
[SourceDate "2018.07.29"]
[SourceVersion "1"]
[SourceVersionDate "2018.07.29"]
[SourceQuality "1"]

1. d4 d5 2. Nf3 Nc6 3. c4 e5 4. dxe5 d4 5. a3 Be6 6. e3 dxe3 7. Qxd8+ Rxd8 8. Bxe3 Nge7 9. Nc3 Ng6 10. Nb5 Rc8 11. Be2 a6 12. Nbd4 Ncxe5 13. Nxe6 fxe6 14. Ng5 Ke7 15. f4 Nf7 16. Nxe6 Nh6 17. Nxf8 Kxf8 18. f5 Ne5 19. 0-0 Nhf7 20. b4 Nd6 21. Rac1 Nd7 22. c5 Nb5 23. a4 Na7 24. Bf3 c6 25. Bd4 Nf6 26. Rcd1 Nd5 27. Bxd5 cxd5 28. f6 1-0

[Event "Berlin Werner Ott op"]
[Site "Berlin"]
[Date "2018.06.30"]
[Round "1"]
[White "Katzenbach, Linus"]
[Black "Krefenstein, Sergej"]
[Result "0-1"]
[ECO "B73"]
[WhiteElo "1716"]
[BlackElo "2119"]
[PlyCount "64"]
[EventDate "2018.06.30"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "CBM 185 Extra"]
[Source "ChessBase"]
[SourceDate "2018.07.29"]
[SourceVersion "1"]
[SourceVersionDate "2018.07.29"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be2 Bg7 7. 0-0 0-0 8. Be3 Nc6 9. h3 Bd7 10. Qd2 Rc8 11. f4 a6 12. a3 Qc7 13. Nb3 Rfd8 14. Rad1 b5 15. Nd5 Qb7 16. Na5 Nxa5 17. Nxe7+ Kh8 18. Nxc8 Rxc8 19. Qxa5 Qxe4 20. Qb6 Re8 21. Rf3 Nd5 22. Rxd5 Qxd5 23. c3 Qc6 24. Rf2 Kg8 25. Bf3 Qxb6 26. Bxb6 Bf5 27. Kh2 Be4 28. Bxe4 Rxe4 29. Rd2 Rxf4 30. Rxd6 Be5 31. Rd8+ Kg7 32. Bd4 Rxd4+ 0-1

[Event "Berlin CupT"]
[Site "Berlin"]
[Date "2018.05.27"]
[Round "3.4"]
[White "Krefenstein, Sergej"]
[Black "Offermann, Fernando"]
[Result "0-1"]
[ECO "E92"]
[WhiteElo "2131"]
[BlackElo "2143"]
[PlyCount "74"]
[EventDate "2018.05.27"]
[EventType "team-k.o."]
[EventRounds "5"]
[EventCountry "GER"]
[SourceTitle "EXT 2022"]
[Source "ChessBase"]
[SourceDate "2021.10.06"]
[SourceVersion "1"]
[SourceVersionDate "2021.10.06"]
[SourceQuality "1"]
[WhiteTeam "Berlin Makkabi"]
[BlackTeam "Berlin SF"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 0-0 5. Nf3 d6 6. Be2 e5 7. d5 a5 8. Bg5 h6 9. Bh4 Na6 10. 0-0 Bd7 11. Nd2 Qe8 12. f3 Nh5 13. Re1 f5 14. exf5 gxf5 15. Bf1 Nf4 16. Bf2 h5 17. g3 Ng6 18. f4 h4 19. Nf3 Bf6 20. Ng5 hxg3 21. hxg3 Kg7 22. Bg2 Bxg5 23. fxg5 Qd8 24. Qd2 Rh8 25. Bf3 Nc5 26. Be3 Rh3 27. Ne2 f4 28. Bxc5 dxc5 29. Bg2 Qxg5 30. Rf1 Rh2 31. Rf2 Rah8 32. Kf1 Rxg2 33. Rxg2 Bh3 34. Ng1 Bxg2+ 35. Qxg2 fxg3 36. Ne2 Rh2 37. Qxg3 Rh1+ 0-1

[Event "Oberliga Nord O 1718"]
[Site "Germany"]
[Date "2018.04.15"]
[Round "9.4"]
[White "Postler, Reinhard"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "B84"]
[WhiteElo "2246"]
[BlackElo "2144"]
[PlyCount "21"]
[EventDate "2017.10.08"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2019"]
[Source "ChessBase"]
[SourceDate "2018.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2018.10.10"]
[SourceQuality "1"]
[WhiteTeam "Berlin Oberschoeneweide"]
[BlackTeam "Berlin Makkabi"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e6 6. Be2 Nc6 7. Be3 a6 8. f4 Qc7 9. 0-0 b5 10. Nxc6 Qxc6 11. Bf3 1/2-1/2

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2018.04.08"]
[Round "9"]
[White "Krefenstein, Sergej"]
[Black "Gelman, Josef"]
[Result "1-0"]
[ECO "E40"]
[WhiteElo "2144"]
[BlackElo "2007"]
[PlyCount "55"]
[EventDate "2018.03.31"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 d5 5. a3 Bxc3+ 6. bxc3 0-0 7. cxd5 exd5 8. Bd3 Re8 9. Ne2 Qd6 10. f3 b6 11. 0-0 Ba6 12. Ng3 Bxd3 13. Qxd3 c5 14. e4 cxd4 15. cxd4 Nfd7 16. e5 Qg6 17. Qb3 Qc6 18. Nf5 Qe6 19. Nd6 Rf8 20. Bd2 Nc6 21. Qa4 Ndb8 22. Rac1 Qd7 23. Rfe1 a6 24. Qb3 Nxd4 25. Qxd5 Ndc6 26. e6 fxe6 27. Rxe6 Kh8 28. Rce1 1-0

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2018.04.07"]
[Round "8"]
[White "Kunz, Andre"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "B22"]
[WhiteElo "2154"]
[BlackElo "2144"]
[PlyCount "75"]
[EventDate "2018.03.31"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. e4 c5 2. d4 cxd4 3. c3 Nf6 4. e5 Nd5 5. Nf3 e6 6. cxd4 d6 7. Bc4 Nc6 8. 0-0 Nb6 9. Bd3 Nb4 10. Be2 Be7 11. Nc3 0-0 12. a3 Nc6 13. Bd3 dxe5 14. dxe5 Nd5 15. Qe2 b6 16. Ne4 Bb7 17. Neg5 g6 18. Qe4 Kg7 19. h4 Qd7 20. h5 Rg8 21. h6+ Kf8 22. Nxh7+ Ke8 23. Nhg5 Bf8 24. h7 Rh8 25. Nh4 Bg7 26. Nxg6 Nde7 27. Nxh8 Bxh8 28. Bf4 Nd4 29. Qe3 Nef5 30. Qh3 Rd8 31. Rad1 Ke7 32. Kh2 f6 33. Ne4 Qe8 34. exf6+ Bxf6 35. Nxf6 Kxf6 36. Rfe1 Qf8 37. Be5+ Ke7 38. h8Q 1-0

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2018.04.06"]
[Round "7"]
[White "Carrasco Jacome, Bryan Ricardo"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "B80"]
[WhiteElo "2101"]
[BlackElo "2144"]
[PlyCount "79"]
[EventDate "2018.03.31"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 Nf6 5. Bd3 d6 6. Nc3 Nbd7 7. Be3 a6 8. Qd2 Qc7 9. f3 Ne5 10. 0-0-0 b5 11. Kb1 Bb7 12. g4 Rc8 13. g5 Nfd7 14. h4 Nb6 15. Qg2 b4 16. Nce2 Nec4 17. Bc1 e5 18. Nf5 g6 19. Ne3 Nxe3 20. Bxe3 Nc4 21. Bc1 h5 22. Ng3 Be7 23. Nf1 Nb6 24. Ne3 0-0 25. b3 d5 26. exd5 Bxd5 27. Bxg6 fxg6 28. Nxd5 Nxd5 29. Rxd5 Rfd8 30. Rhd1 Bc5 31. Qe2 Bd4 32. Rxd8+ Rxd8 33. Qxa6 Qc3 34. Qxg6+ Kf8 35. Qf6+ Ke8 36. Qe6+ Kf8 37. Rxd4 Rxd4 38. g6 Rf4 39. Bxf4 Qe1+ 40. Bc1 1-0

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2018.04.05"]
[Round "6"]
[White "Krefenstein, Sergej"]
[Black "Donath, Johann"]
[Result "1/2-1/2"]
[ECO "D20"]
[WhiteElo "2144"]
[BlackElo "2085"]
[PlyCount "55"]
[EventDate "2018.03.31"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. d4 d5 2. c4 dxc4 3. e4 Nf6 4. e5 Nd5 5. Bxc4 Nb6 6. Bb3 Nc6 7. Ne2 Bf5 8. Nbc3 e6 9. Be3 Qd7 10. 0-0 0-0-0 11. Na4 f6 12. Nxb6+ axb6 13. Rc1 Kb8 14. f3 fxe5 15. dxe5 Qe8 16. Qe1 Nxe5 17. Qc3 Bd6 18. Nd4 Nd3 19. Rcd1 Nf4 20. Bxf4 Bxf4 21. Nxf5 exf5 22. Rxd8+ Qxd8 23. Qxg7 Re8 24. Qf7 Re2 25. Qg8 Re8 26. Qf7 Re2 27. Qg8 Re8 28. Qf7 1/2-1/2

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2018.04.04"]
[Round "5"]
[White "Kunze, Martin"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "D74"]
[WhiteElo "2108"]
[BlackElo "2144"]
[PlyCount "73"]
[EventDate "2018.03.31"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 g6 3. Nf3 Bg7 4. g3 d5 5. cxd5 Nxd5 6. Bg2 0-0 7. 0-0 c6 8. e4 Nf6 9. Re1 Na6 10. Nc3 Be6 11. h3 h6 12. Be3 Kh7 13. Kh2 Qa5 14. Nd2 Rfd8 15. a3 Nc7 16. d5 cxd5 17. Nb3 Qa6 18. Bf1 b5 19. Nc5 Qc6 20. Nxe6 fxe6 21. e5 Nd7 22. Bd4 Nf8 23. Bd3 Qe8 24. h4 Kg8 25. h5 a5 26. Ne2 g5 27. g4 Qf7 28. Kg2 Rdc8 29. f4 gxf4 30. Rf1 Bh8 31. Nxf4 Qg7 32. Ng6 Nxg6 33. Bxg6 Rf8 34. Qc2 Ne8 35. Rxf8+ Qxf8 36. Bh7+ Kf7 37. Qg6# 1-0

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2018.04.03"]
[Round "4"]
[White "Krefenstein, Sergej"]
[Black "Dimitrijeski, Kristian"]
[Result "1-0"]
[ECO "D18"]
[WhiteElo "2144"]
[BlackElo "2184"]
[PlyCount "125"]
[EventDate "2018.03.31"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 dxc4 5. a4 Bf5 6. Nh4 e6 7. Nxf5 exf5 8. e3 Bb4 9. Bxc4 0-0 10. Qc2 g6 11. 0-0 Nbd7 12. Ba2 Qe7 13. Bd2 Rad8 14. Rad1 Ne4 15. Bc1 Nef6 16. Kh1 Nb6 17. f3 Rd7 18. e4 c5 19. exf5 cxd4 20. Ne4 Nxe4 21. fxe4 d3 22. Qf2 Qxe4 23. fxg6 Qxg6 24. Qh4 Be7 25. Qh3 Rd4 26. a5 Nc8 27. Bd2 Rh4 28. Qf3 Nd6 29. Be1 Rh5 30. Rxd3 Ne4 31. Rd5 Ng5 32. Qf5 Qe6 33. Qxe6 fxe6 34. Rxf8+ Kxf8 35. Rb5 a6 36. Rxb7 Ne4 37. Kg1 Bc5+ 38. Kf1 Rxh2 39. Bxe6 Rh6 40. Bd5 Nd6 41. Rc7 Bd4 42. b4 Nb5 43. Rc6 Rh5 44. Bf3 Rh1+ 45. Ke2 Be5 46. Rxa6 Nd4+ 47. Kf2 Nc2 48. Bd2 Rb1 49. Ra8+ Kg7 50. Be4 Rb2 51. Bxc2 Rxc2 52. Ke3 Bf4+ 53. Kxf4 Rxd2 54. Rb8 Rxg2 55. a6 Ra2 56. b5 Ra4+ 57. Ke5 h5 58. Kd6 h4 59. Re8 h3 60. Re1 h2 61. Rh1 Ra2 62. Kc6 Kf6 63. Kb7 1-0

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2018.04.02"]
[Round "3"]
[White "Engers, Felix"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "A20"]
[WhiteElo "2024"]
[BlackElo "2144"]
[PlyCount "81"]
[EventDate "2018.03.31"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. c4 e5 2. g3 c6 3. Nf3 e4 4. Nd4 d5 5. d3 Nf6 6. Bg2 Bb4+ 7. Nc3 dxc4 8. dxe4 c5 9. Ndb5 Qxd1+ 10. Kxd1 Na6 11. Nd6+ Ke7 12. e5 Bxc3 13. bxc3 Ng4 14. Kc2 Rb8 15. Bf4 Nc7 16. h3 Nh6 17. Bg5+ Ke6 18. h4 Kxe5 19. Bxh6 gxh6 20. Nxf7+ Kf6 21. Nxh8 Bf5+ 22. e4 Bd7 23. Kd2 Rxh8 24. Ke3 Ba4 25. f4 b5 26. e5+ Ke7 27. a3 Rg8 28. Rh3 Ke6 29. Be4 Rd8 30. Rh2 Nd5+ 31. Bxd5+ Rxd5 32. Rd2 a5 33. Rxd5 Kxd5 34. Ra2 Ke6 35. Rd2 b4 36. axb4 cxb4 37. Rd6+ Ke7 38. Kd4 Bb3 39. Ra6 Bd1 40. cxb4 axb4 41. Ra7+ 1-0

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2018.04.01"]
[Round "2"]
[White "Krefenstein, Sergej"]
[Black "Lassan, Christian"]
[Result "1-0"]
[ECO "D36"]
[WhiteElo "2144"]
[BlackElo "2117"]
[PlyCount "89"]
[EventDate "2018.03.31"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 e6 3. Nc3 d5 4. cxd5 exd5 5. Bg5 Nbd7 6. e3 c6 7. Bd3 Be7 8. Qc2 Nh5 9. Bxe7 Qxe7 10. Nge2 g6 11. 0-0-0 Nb6 12. Kb1 Ng7 13. Ng3 Be6 14. Na4 Nxa4 15. Qxa4 0-0 16. Rc1 Qf6 17. Qc2 Rac8 18. Qe2 Rfd8 19. Rhd1 h5 20. Qf3 Qe7 21. h3 h4 22. Ne2 Bf5 23. Nf4 Bxd3+ 24. Nxd3 Nf5 25. Qf4 Re8 26. Ne5 c5 27. Ng4 c4 28. Qe5 Qxe5 29. dxe5 Kg7 30. Rxd5 Re6 31. Rd7 Rb6 32. e4 Nh6 33. Nxh6 Kxh6 34. Rxf7 c3 35. Rc2 Rc5 36. f3 Rcb5 37. b3 Rc6 38. e6 Re5 39. Rxb7 Rexe6 40. Rd7 Kg5 41. Rd3 Kf4 42. Rcxc3 Kg3 43. Rxc6 Rxc6 44. Rd2 Rc3 45. Re2 1-0

[Event "Berlin-ch MT"]
[Site "Berlin"]
[Date "2018.03.31"]
[Round "1"]
[White "Knopf, Roland"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "D00"]
[WhiteElo "1877"]
[BlackElo "2144"]
[PlyCount "65"]
[EventDate "2018.03.31"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2020"]
[Source "ChessBase"]
[SourceDate "2019.10.17"]
[SourceVersion "1"]
[SourceVersionDate "2019.10.17"]
[SourceQuality "1"]

1. d4 Nf6 2. Nf3 g6 3. Nc3 d5 4. e3 Bg7 5. Be2 0-0 6. 0-0 c6 7. b3 Nbd7 8. Bb2 Qc7 9. Na4 Ne4 10. c4 dxc4 11. bxc4 c5 12. Qc2 Nd6 13. Rac1 b6 14. Nc3 Bb7 15. d5 Rad8 16. Bd3 Rfe8 17. Ne4 e5 18. Nxd6 Qxd6 19. e4 Bc8 20. Rb1 Bh6 21. Bc1 Bxc1 22. Qxc1 Nf6 23. Re1 Nh5 24. Bf1 Nf4 25. g3 Nh3+ 26. Bxh3 Bxh3 27. Qh6 Bc8 28. Ng5 Qf6 29. Qxh7+ Kf8 30. Qh4 Kg7 31. Qh7+ Kf8 32. Qh4 Kg7 33. Qh7+ 1/2-1/2

[Event "Oberliga Nord O 1718"]
[Site "Germany"]
[Date "2018.03.18"]
[Round "8.4"]
[White "Krefenstein, Sergej"]
[Black "Venske, Kai Gerrit"]
[Result "1-0"]
[ECO "A80"]
[WhiteElo "2144"]
[BlackElo "2183"]
[PlyCount "111"]
[EventDate "2017.10.08"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2019"]
[Source "ChessBase"]
[SourceDate "2018.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2018.10.10"]
[SourceQuality "1"]
[WhiteTeam "Berlin Makkabi"]
[BlackTeam "Berlin Weisse Dame"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. d4 f5 2. Nc3 d5 3. Bf4 a6 4. e3 e6 5. Nf3 Nf6 6. Bd3 c5 7. Ne5 Nc6 8. 0-0 cxd4 9. Nxc6 bxc6 10. exd4 c5 11. dxc5 Bxc5 12. Na4 Bd6 13. Bxd6 Qxd6 14. Qe2 Bd7 15. Nc3 0-0 16. Rae1 Rfe8 17. Qe5 Qb6 18. Ne2 Rab8 19. b3 Ng4 20. Qd4 Qd6 21. f4 a5 22. c4 Rb4 23. Nc3 Rc8 24. h3 Nf6 25. Rb1 Qb8 26. Qe3 a4 27. Nb5 axb3 28. axb3 Ne4 29. Nd4 Qb6 30. Rfe1 Rb8 31. Rbc1 Kh8 32. Kh2 h6 33. Bxe4 fxe4 34. c5 Qc7 35. c6 Bc8 36. Kh1 e5 37. fxe5 Qxe5 38. Red1 R8b6 39. Ra1 Ba6 40. Rac1 Qd6 41. c7 Bc8 42. Rf1 Kg8 43. Qc3 g6 44. Rf2 Rb7 45. Rcf1 Rxd4 46. Qxd4 Rxc7 47. Rf6 Qe7 48. Rxg6+ Kh7 49. Rgf6 Rd7 50. Rf8 Qg7 51. Qxg7+ Kxg7 52. Rxc8 e3 53. Re8 d4 54. Rd1 Kf6 55. Kg1 Kf5 56. Rxe3 1-0

[Event "Oberliga Nord O 1718"]
[Site "Germany"]
[Date "2018.02.25"]
[Round "7.4"]
[White "Meissner, Hans Juergen"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "D90"]
[WhiteElo "2286"]
[BlackElo "2144"]
[PlyCount "106"]
[EventDate "2017.10.08"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2019"]
[Source "ChessBase"]
[SourceDate "2018.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2018.10.10"]
[SourceQuality "1"]
[WhiteTeam "Berlin Empor"]
[BlackTeam "Berlin Makkabi"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. d4 Nf6 2. Nf3 g6 3. c4 Bg7 4. Nc3 d5 5. cxd5 Nxd5 6. Bg5 c5 7. Rc1 Nxc3 8. bxc3 0-0 9. Qd2 Bg4 10. e3 Bxf3 11. gxf3 Nc6 12. Be2 Qd7 13. h4 Rad8 14. Qb2 h6 15. Bf4 e5 16. dxe5 Nxe5 17. Bxe5 Bxe5 18. f4 Bf6 19. h5 Qd5 20. Rg1 g5 21. fxg5 hxg5 22. Qc2 Kh8 23. c4 Qe5 24. Bf3 Rd7 25. Ke2 Rfd8 26. Rgd1 Rxd1 27. Rxd1 Rxd1 28. Kxd1 b6 29. Ke2 Kg7 30. a4 Qb2 31. Qxb2 Bxb2 32. Kd3 f5 33. Bc6 Kh6 34. Bd7 Kxh5 35. Bxf5 g4 36. Bd7 Kg5 37. Bc8 Ba3 38. Ke2 Bb2 39. Kd2 Ba3 40. Bd7 Bb4+ 41. Kd3 Be1 42. Ke2 Bc3 43. Kf1 Bb2 44. Kg2 Bc3 45. Bc8 Bf6 46. Kg3 Be5+ 47. f4+ gxf3+ 48. Kxf3 Bb2 49. Ke4 Bc1 50. Kd5 Bxe3 51. Kc6 Bd2 52. Kb7 Kf4 53. Kxa7 Ba5 1/2-1/2

[Event "Oberliga Nord O 1718"]
[Site "Germany"]
[Date "2018.02.04"]
[Round "6.3"]
[White "Giemsa, Stephan"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "D80"]
[WhiteElo "2281"]
[BlackElo "2144"]
[PlyCount "7"]
[EventDate "2017.10.08"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2019"]
[Source "ChessBase"]
[SourceDate "2018.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2018.10.10"]
[SourceQuality "1"]
[WhiteTeam "Berlin Tegel II"]
[BlackTeam "Berlin Makkabi"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 1/2-1/2

[Event "Oberliga Nord O 1718"]
[Site "Germany"]
[Date "2018.01.21"]
[Round "5.4"]
[White "Krefenstein, Sergej"]
[Black "Gropp, Andreas"]
[Result "1/2-1/2"]
[ECO "A90"]
[WhiteElo "2144"]
[BlackElo "2147"]
[PlyCount "85"]
[EventDate "2017.10.08"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2019"]
[Source "ChessBase"]
[SourceDate "2018.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2018.10.10"]
[SourceQuality "1"]
[WhiteTeam "Berlin Makkabi"]
[BlackTeam "Neuruppin"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. d4 e6 2. c4 f5 3. Nc3 Nf6 4. g3 d5 5. Bg2 c6 6. Nf3 Bd6 7. 0-0 0-0 8. Qc2 Qe8 9. Nd2 Qh5 10. f4 Nbd7 11. Nf3 Ne4 12. Nxe4 fxe4 13. Ne5 Nxe5 14. fxe5 Rxf1+ 15. Bxf1 Be7 16. Be3 Bd7 17. c5 Qg4 18. Bg2 Rf8 19. Qd2 b6 20. b4 bxc5 21. bxc5 Bc8 22. Rf1 Ba6 23. Rxf8+ Kxf8 24. Kf2 Bd8 25. Bf1 h5 26. h4 Qf5+ 27. Kg1 Qg4 28. Kh2 Kf7 29. Qe1 g6 30. Qf2+ Qf5 31. Bf4 Ke8 32. Bh3 Qf7 33. Qe3 Bc4 34. Qd2 Kd7 35. a3 a6 36. Kg2 Bb5 37. Qe1 Bxh4 38. Be3 Bd8 39. g4 hxg4 40. Bxg4 Qh7 41. Qg3 Bh4 42. Qh3 Qe7 43. Bxe6+ 1/2-1/2

[Event "Oberliga Nord O 1718"]
[Site "Germany"]
[Date "2017.12.10"]
[Round "4.4"]
[White "Kunze, Kerstin"]
[Black "Krefenstein, Sergej"]
[Result "1/2-1/2"]
[ECO "C88"]
[WhiteElo "2082"]
[BlackElo "2144"]
[PlyCount "71"]
[EventDate "2017.10.08"]
[EventType "team-tourn"]
[EventRounds "9"]
[EventCountry "GER"]
[SourceTitle "EXT 2019"]
[Source "ChessBase"]
[SourceDate "2018.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2018.10.10"]
[SourceQuality "1"]
[WhiteTeam "Cottbus Lokomotive"]
[BlackTeam "Berlin Makkabi"]
[WhiteTeamCountry "GER"]
[BlackTeamCountry "GER"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. 0-0 Be7 6. Re1 b5 7. Bb3 0-0 8. a4 Rb8 9. axb5 axb5 10. c3 d6 11. h3 Re8 12. d4 exd4 13. cxd4 Bf8 14. Ng5 Re7 15. Nc3 Qe8 16. Bf4 b4 17. Nd5 Nxd5 18. Bxd5 Nd8 19. e5 dxe5 20. Bxe5 Qd7 21. Qd3 Qf5 22. Qg3 Bb7 23. Bxb7 Rxb7 24. Bxg7 Rb5 25. Bxf8 Rxe1+ 26. Rxe1 Kxf8 27. Nf3 Ne6 28. Qh4 Rd5 29. Qh6+ Ke7 30. Qc1 Kf6 31. Qh6+ Qg6 32. Qh4+ Kg7 33. Ne5 Qg5 34. Qxg5+ Nxg5 35. Nc6 Rd6 36. Nxb4 1/2-1/2

[Event "Berlin Eckbauer op 20th"]
[Site "Berlin"]
[Date "2017.11.27"]
[Round "7"]
[White "Krefenstein, Sergej"]
[Black "Godoj, Veit"]
[Result "1-0"]
[ECO "E91"]
[WhiteElo "2172"]
[BlackElo "2017"]
[PlyCount "92"]
[EventDate "2017.10.09"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "GER"]
[SourceTitle "CBM 189 Extra"]
[Source "ChessBase"]
[SourceDate "2019.06.03"]
[SourceVersion "1"]
[SourceVersionDate "2019.06.03"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Be2 0-0 6. Nf3 Nbd7 7. Bg5 h6 8. Be3 Ng4 9. Bf4 e5 10. Bg3 exd4 11. Nxd4 Nge5 12. 0-0 Nc6 13. Nc2 Re8 14. f3 Nc5 15. Qd2 a5 16. Rad1 Kh7 17. Bf2 b6 18. Rfe1 Bb7 19. Bf1 Qd7 20. Ne3 Ne7 21. Bg3 Ng8 22. Ned5 Rad8 23. Bh4 Rc8 24. b3 Qe6 25. Nb5 Bxd5 26. cxd5 Qe5 27. Nd4 Qxd4+ 28. Qxd4 Bxd4+ 29. Rxd4 g5 30. Bf2 f6 31. Bb5 Rf8 32. h4 Ne7 33. h5 Rcd8 34. Rd2 Nc8 35. g4 Na7 36. Bd3 Kg7 37. Rc1 Rf7 38. Kg2 Nxd3 39. Rxd3 Rb8 40. Bd4 Nb5 41. Bb2 Rb7 42. f4 Kg8 43. Rf3 Rb8 44. fxg5 fxg5 45. Rxf7 Kxf7 46. a4 Na7 1-0

[Event "Berlin Eckbauer op 20th"]
[Site "Berlin"]
[Date "2017.11.20"]
[Round "6"]
[White "Brustkern, Juergen"]
[Black "Krefenstein, Sergej"]
[Result "1-0"]
[ECO "D00"]
[WhiteElo "2287"]
[BlackElo "2172"]
[PlyCount "75"]
[EventDate "2017.10.09"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "GER"]
[SourceTitle "CBM 189 Extra"]
[Source "ChessBase"]
[SourceDate "2019.06.03"]
[SourceVersion "1"]
[SourceVersionDate "2019.06.03"]
[SourceQuality "1"]

1. d4 d5 2. Bg5 h6 3. Bh4 c5 4. Nc3 Nc6 5. e3 Qa5 6. Nf3 e6 7. a3 Nge7 8. dxc5 Nf5 9. b4 Qc7 10. Nb5 Qb8 11. Bg3 Nxg3 12. hxg3 Be7 13. c4 a6 14. Nc3 dxc4 15. Bxc4 0-0 16. 0-0 b6 17. cxb6 Qxb6 18. Rc1 Rd8 19. Qe2 Bb7 20. Na4 Qa7 21. Bd3 Rd7 22. Nc5 Rc7 23. Nxb7 Qxb7 24. Be4 Bf6 25. Rc5 Rac8 26. Rfc1 Be7 27. R5c4 f5 28. Bxc6 Rxc6 29. Nd4 Rxc4 30. Rxc4 Kf7 31. Qc2 Rd8 32. Rc7 Qd5 33. Qc6 Kf6 34. Qxa6 Ra8 35. Qd3 g6 36. Qc3 Kf7 37. Qc6 Qe5 38. Rxe7+ 1-0

