[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2013.07.02"]
[Round "7"]
[White "Van den Biggelaar, Don"]
[Black "Zwaan, Gert Jan"]
[Result "1-0"]
[ECO "A30"]
[PlyCount "87"]
[EventDate "2013.05.21"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2014"]
[Source "ChessBase"]
[SourceDate "2013.11.20"]
[SourceVersion "1"]
[SourceVersionDate "2013.11.20"]
[SourceQuality "1"]

1. c4 c5 2. Nc3 Nc6 3. Nf3 Nf6 4. g3 b6 5. Bg2 Bb7 6. 0-0 e6 7. e4 Be7 8. d3 0-0 9. Bf4 Nh5 10. Be3 a6 11. Qb3 Rb8 12. Rad1 g6 13. d4 Na5 14. Qc2 Nxc4 15. Bh6 Re8 16. dxc5 bxc5 17. b3 Na3 18. Qd3 d6 19. Nd2 Qc7 20. f4 Red8 21. f5 exf5 22. Nd5 Bxd5 23. Qxd5 Nf6 24. Qd3 Ng4 25. Bf4 g5 26. Be3 Nxe3 27. Qxe3 Nc2 28. Qf2 Nd4 29. exf5 f6 30. Bd5+ Kh8 31. Nf3 Nxf3+ 32. Qxf3 Bf8 33. Rde1 Re8 34. Qh5 Rxe1 35. Rxe1 Qg7 36. Re6 a5 37. Qe2 a4 38. bxa4 Qa7 39. Rxf6 c4+ 40. Kg2 Qxa4 41. Qe6 Qxa2+ 42. Kh3 g4+ 43. Kxg4 Qa7 44. Qg8# 1-0

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2013.06.25"]
[Round "6"]
[White "Zwaan, Gert Jan"]
[Black "De Ruyter, Wim"]
[Result "0-1"]
[ECO "C48"]
[PlyCount "30"]
[EventDate "2013.05.21"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2014"]
[Source "ChessBase"]
[SourceDate "2013.11.20"]
[SourceVersion "1"]
[SourceVersionDate "2013.11.20"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Nc3 Bc5 4. Bb5 Nf6 5. Bxc6 dxc6 6. 0-0 Bg4 7. d3 0-0 8. h3 Bh5 9. g4 Nxg4 10. hxg4 Bxg4 11. Bg5 Qd6 12. Kg2 Qg6 13. Bh4 Bxf3+ 14. Kxf3 f5 15. Rh1 Qg4# 0-1

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2013.06.18"]
[Round "5"]
[White "Zwaan, Gert Jan"]
[Black "Schaeffner, Joost"]
[Result "1/2-1/2"]
[ECO "C11"]
[PlyCount "50"]
[EventDate "2013.05.21"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2014"]
[Source "ChessBase"]
[SourceDate "2013.11.20"]
[SourceVersion "1"]
[SourceVersionDate "2013.11.20"]
[SourceQuality "1"]

1. e4 e6 2. d4 d5 3. Nc3 Nf6 4. e5 Nfd7 5. f4 c5 6. Nf3 Nc6 7. Be3 a6 8. Qd2 b5 9. a3 Qb6 10. Qf2 cxd4 11. Bxd4 Nxd4 12. Nxd4 Bc5 13. Rd1 b4 14. axb4 Qxb4 15. Qd2 Rb8 16. Nc6 Qxb2 17. Rb1 Qxb1+ 18. Nxb1 Rxb1+ 19. Ke2 a5 20. Qxa5 0-0 21. Qa2 Rb6 22. Qa4 Ra6 23. Qb5 Rb6 24. Qa4 Ra6 25. Qb5 Ra1 1/2-1/2

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2013.06.04"]
[Round "3"]
[White "Verschoor, Marcel"]
[Black "Zwaan, Gert Jan"]
[Result "0-1"]
[ECO "B33"]
[PlyCount "82"]
[EventDate "2013.05.21"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2014"]
[Source "ChessBase"]
[SourceDate "2013.11.20"]
[SourceVersion "1"]
[SourceVersionDate "2013.11.20"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 d6 5. Nc3 Nf6 6. Bb5 Bd7 7. 0-0 e6 8. Kh1 Be7 9. f4 0-0 10. Nb3 a6 11. Be2 Qc7 12. Be3 b5 13. a3 Bc8 14. Bf3 Bb7 15. Qe2 Rfe8 16. Rad1 b4 17. axb4 Nxb4 18. Rd4 a5 19. Rc4 Qb8 20. Qf2 Ba6 21. Rxb4 axb4 22. Ne2 Bxe2 23. Qxe2 Ra2 24. Rd1 Rd8 25. Nd4 Qc8 26. g4 d5 27. exd5 exd5 28. g5 Ne4 29. Bg4 Qc4 30. Qxc4 dxc4 31. Nc6 Rxd1+ 32. Bxd1 Bf8 33. Bf3 f5 34. Bd4 c3 35. bxc3 bxc3 36. Be2 Rxc2 37. Bc4+ Kh8 38. Ne5 Nd6 39. Bd3 Rc1+ 40. Kg2 c2 41. Kg3 Rd1 0-1

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2013.05.28"]
[Round "2"]
[White "Lauer, Albert"]
[Black "Zwaan, Gert Jan"]
[Result "1-0"]
[ECO "D07"]
[WhiteElo "1886"]
[PlyCount "61"]
[EventDate "2013.05.21"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2014"]
[Source "ChessBase"]
[SourceDate "2013.11.20"]
[SourceVersion "1"]
[SourceVersionDate "2013.11.20"]
[SourceQuality "1"]

1. d4 d5 2. c4 Nc6 3. cxd5 Qxd5 4. Nf3 e5 5. Nc3 Bb4 6. a3 Bxc3+ 7. bxc3 e4 8. Nd2 Nf6 9. e3 0-0 10. Qc2 Re8 11. c4 Qh5 12. d5 Nd4 13. Qb1 Bg4 14. Bb2 Nf5 15. Bxf6 gxf6 16. Nxe4 Qh6 17. Qd3 Nxe3 18. Qxe3 Qxe3+ 19. fxe3 Rxe4 20. Kd2 Rae8 21. Re1 Bd7 22. Bd3 R4e5 23. Rhf1 Kg7 24. Rf4 h5 25. Ref1 Rxe3 26. Rxf6 R3e7 27. c5 a6 28. d6 cxd6 29. cxd6 Re1 30. Rxf7+ Kh8 31. Rxe1 1-0

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2013.05.21"]
[Round "1"]
[White "Zwaan, Gert Jan"]
[Black "De Jeu, Marcel"]
[Result "0-1"]
[ECO "B07"]
[PlyCount "44"]
[EventDate "2013.05.21"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2014"]
[Source "ChessBase"]
[SourceDate "2013.11.20"]
[SourceVersion "1"]
[SourceVersionDate "2013.11.20"]
[SourceQuality "1"]

1. e4 d6 2. Nf3 g6 3. d4 Nf6 4. Bd3 Bg7 5. c3 0-0 6. 0-0 Nc6 7. Re1 e5 8. Nbd2 Nh5 9. Bb5 exd4 10. Bxc6 dxc3 11. Nc4 bxc6 12. e5 cxb2 13. Bxb2 Be6 14. Na5 Qd7 15. Rc1 Rab8 16. Ba1 Bd5 17. Qa4 Bxf3 18. gxf3 Bh6 19. Qh4 Bxc1 20. Rxc1 c5 21. Kh1 Qf5 22. Rg1 Qxf3+ 0-1

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2007.06.19"]
[Round "6"]
[White "Irwin, Mark"]
[Black "Zwaan, Gert Jan"]
[Result "1-0"]
[ECO "B70"]
[WhiteElo "2280"]
[BlackElo "1511"]
[PlyCount "57"]
[EventDate "2007.05.15"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[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. Bg5 Nc6 9. Nb3 a6 10. f4 b5 11. Bf3 Bb7 12. Kh1 Qc7 13. Re1 Rfd8 14. Nd5 Nxd5 15. exd5 Nb8 16. Rxe7 Nd7 17. c3 Re8 18. Qe2 Qc8 19. Na5 Rf8 20. Bg4 f5 21. Qe6+ Kh8 22. Nxb7 Qxb7 23. Rxd7 Qb8 24. Qe7 Rg8 25. Bf6 Qf8 26. Qxf8 Raxf8 27. Bxg7+ Rxg7 28. Rxg7 Kxg7 29. Bf3 1-0

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2007.06.12"]
[Round "5"]
[White "Zwaan, Gert Jan"]
[Black "Loomans, Nico"]
[Result "1-0"]
[ECO "B32"]
[WhiteElo "1511"]
[BlackElo "1507"]
[PlyCount "106"]
[EventDate "2007.05.15"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 e5 5. Nf3 Nf6 6. Bg5 Be7 7. Nc3 Qb6 8. Bxf6 Bxf6 9. Nd5 Qa5+ 10. c3 Qd8 11. b4 0-0 12. Bc4 d6 13. h3 Be6 14. Qd2 Be7 15. Rd1 a6 16. Nxe7+ Qxe7 17. Bxe6 Qxe6 18. Qxd6 Qc4 19. Qd3 Qxa2 20. 0-0 Rad8 21. Qe3 Qb3 22. Rb1 Qc4 23. Rfe1 Rd3 24. Qc1 Rxc3 25. Qb2 Rd8 26. b5 axb5 27. Qxb5 Qxb5 28. Rxb5 Rb8 29. Nxe5 Nxe5 30. Rxe5 b5 31. Rb1 f6 32. Rexb5 Rbc8 33. Rb8 Kf7 34. Rxc8 Rxc8 35. f3 Rc7 36. Kf2 g5 37. Re1 Ke6 38. Kg3 h5 39. h4 Rc2 40. hxg5 fxg5 41. Ra1 h4+ 42. Kh3 Ke5 43. Ra5+ Kf4 44. Rf5+ Ke3 45. Rxg5 Rc1 46. Kxh4 Rh1+ 47. Kg3 Rh8 48. e5 Re8 49. f4 Ke4 50. Kg4 Rb8 51. g3 Rh8 52. e6 Rh7 53. Re5+ Kd4 1-0

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2007.06.05"]
[Round "4"]
[White "Sonneveldt, Peter"]
[Black "Zwaan, Gert Jan"]
[Result "1/2-1/2"]
[ECO "A34"]
[WhiteElo "1657"]
[BlackElo "1511"]
[PlyCount "104"]
[EventDate "2007.05.15"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 c5 2. c4 d6 3. Nf3 Bg4 4. Be2 Nc6 5. Nc3 Nf6 6. d3 e6 7. Ng5 Bxe2 8. Qxe2 Nd4 9. Qd1 Be7 10. f4 e5 11. f5 Qd7 12. 0-0 h6 13. Nf3 a6 14. a4 Nc6 15. b3 Qd8 16. Bd2 Nb4 17. Be1 h5 18. Nd5 Nbxd5 19. cxd5 Qb6 20. Kh1 Ng4 21. Qb1 Qc7 22. Nd2 Nf6 23. Nc4 Bd8 24. Qb2 b6 25. Qe2 Rb8 26. Bd2 Qe7 27. Rfe1 a5 28. Qf3 Kd7 29. Rf1 Bc7 30. Rab1 Rbg8 31. Bg5 Bd8 32. Ne3 Qf8 33. Qe2 Kc7 34. Qc2 g6 35. Qf2 Ng4 36. Bxd8+ Kxd8 37. Qe2 f6 38. Nxg4 hxg4 39. Qxg4 g5 40. Qe2 Rh6 41. Rb2 Qg7 42. Rf2 Qh7 43. g3 Rh3 44. Rg2 Rh8 45. Kg1 Rh6 46. Qc2 Qc7 47. Qc4 R8h7 48. Rbf2 Ke7 49. Qc2 Kd8 50. Qd2 Kc8 51. Qc2 Kb8 52. Qc4 Qd7 1/2-1/2

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2007.05.29"]
[Round "3"]
[White "Zwaan, Gert Jan"]
[Black "Oudshoorn, Arres"]
[Result "0-1"]
[ECO "B71"]
[WhiteElo "1511"]
[BlackElo "1767"]
[PlyCount "64"]
[EventDate "2007.05.15"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. f4 Bg7 7. e5 dxe5 8. fxe5 Nfd7 9. e6 Ne5 10. Bb5+ Nbc6 11. Bxc6+ bxc6 12. exf7+ Nxf7 13. Be3 Bd7 14. 0-0 0-0 15. Qd2 Qc7 16. Nf3 Ne5 17. Bf4 Nxf3+ 18. Rxf3 Qb6+ 19. Kh1 Bg4 20. Rff1 Qxb2 21. Ne4 Rad8 22. Qe1 Qxc2 23. Rc1 Qe2 24. Qxe2 Bxe2 25. Rf2 Bc4 26. Be3 Rxf2 27. Bxf2 Bxa2 28. Bxa7 Bd5 29. Ng5 Bh6 30. h4 Ra8 31. Bc5 Ra4 32. Nf3 Bxc1 0-1

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2007.05.15"]
[Round "1"]
[White "Oosthout, Wouter"]
[Black "Zwaan, Gert Jan"]
[Result "1-0"]
[ECO "B23"]
[WhiteElo "1950"]
[BlackElo "1511"]
[PlyCount "57"]
[EventDate "2007.05.15"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 c5 2. Nc3 a6 3. g3 b5 4. Bg2 Bb7 5. d3 f5 6. Nf3 b4 7. Na4 Qa5 8. b3 fxe4 9. Ne5 Nf6 10. dxe4 d6 11. Nc4 Qc7 12. Nab6 Ra7 13. Nd5 Bxd5 14. exd5 Nbd7 15. Bb2 g6 16. Qe2 Bg7 17. Rd1 0-0 18. 0-0 Nb6 19. Ne3 Qc8 20. h3 Rc7 21. g4 h6 22. f4 c4 23. Bd4 Rc5 24. Kh1 cxb3 25. Bxc5 Qxc5 26. cxb3 Qc8 27. Rc1 Qb7 28. Qd3 Ne8 29. Qxg6 1-0

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2006.06.27"]
[Round "7"]
[White "Gorter, Peter"]
[Black "Zwaan, Gert Jan"]
[Result "1/2-1/2"]
[ECO "B38"]
[WhiteElo "1392"]
[BlackElo "1516"]
[PlyCount "46"]
[EventDate "2006.05.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 d6 5. c4 Nf6 6. Nc3 g6 7. f3 Bg7 8. Be3 0-0 9. Qd2 a6 10. Nxc6 bxc6 11. Bh6 Rb8 12. Bxg7 Kxg7 13. 0-0-0 Qa5 14. g4 Be6 15. Qc2 Qc5 16. Na4 Qe3+ 17. Qd2 Qxf3 18. Be2 Qxe4 19. g5 Ng8 20. h4 Bxc4 21. Qc3+ f6 22. Bxc4 c5 23. b3 Qb7 1/2-1/2

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2006.06.20"]
[Round "6"]
[White "Zwaan, Gert Jan"]
[Black "Aalbers, Klaas"]
[Result "0-1"]
[ECO "C40"]
[WhiteElo "1516"]
[BlackElo "1793"]
[PlyCount "72"]
[EventDate "2006.05.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 f5 3. exf5 Bc5 4. Bc4 d5 5. Bb3 Nc6 6. Qe2 e4 7. d3 Bxf5 8. Bg5 Be7 9. Bxe7 Qxe7 10. Bxd5 exf3 11. Qxe7+ Ngxe7 12. Bxf3 Nd4 13. Na3 Nxf3+ 14. gxf3 Nc6 15. 0-0-0 0-0-0 16. Kb1 Rhe8 17. Nc4 Re2 18. Ne3 Bg6 19. Rhf1 Rf8 20. Rde1 Rxe1+ 21. Rxe1 Rxf3 22. Rf1 Nd4 23. Nd5 Nc6 24. a3 Rxd3 25. Nf4 Rd2 26. Nxg6 hxg6 27. c3 Re2 28. h4 Re6 29. Rg1 Rf6 30. Rg2 Ne5 31. Kc2 Kd7 32. Kd2 Nf3+ 33. Ke3 Nxh4 34. Rh2 Nf5+ 35. Ke2 Rd6 36. b4 Ra6 0-1

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2006.06.13"]
[Round "5"]
[White "Volders, Wessel"]
[Black "Zwaan, Gert Jan"]
[Result "1-0"]
[ECO "B30"]
[WhiteElo "1899"]
[BlackElo "1516"]
[PlyCount "77"]
[EventDate "2006.05.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. Bb5 e6 4. 0-0 Nge7 5. c3 a6 6. Bxc6 bxc6 7. e5 Ng6 8. Na3 Be7 9. Nc4 Qc7 10. d3 0-0 11. Re1 Bb7 12. Bg5 f6 13. exf6 Bxf6 14. h4 Bxg5 15. hxg5 Rae8 16. Qb3 Rb8 17. Qb6 Qxb6 18. Nxb6 Bc8 19. Nxc8 Rbxc8 20. Ne5 Nxe5 21. Rxe5 Rf5 22. Rxf5 exf5 23. Re1 d6 24. Re7 Rb8 25. b3 g6 26. Ra7 Rb6 27. Kf1 Kh8 28. Ke2 d5 29. c4 d4 30. Kf3 Rb8 31. Rxa6 Rc8 32. Rb6 h6 33. Kf4 hxg5+ 34. Kxg5 Rc7 35. a4 Ra7 36. Rxc6 Rb7 37. a5 Rxb3 38. a6 Rxd3 39. Kxg6 1-0

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2006.06.06"]
[Round "4"]
[White "Zwaan, Gert Jan"]
[Black "Walraven, Maurice"]
[Result "1/2-1/2"]
[ECO "C40"]
[WhiteElo "1516"]
[BlackElo "1588"]
[PlyCount "66"]
[EventDate "2006.05.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 f5 3. exf5 e4 4. Ne5 Nf6 5. Be2 d6 6. Bh5+ Ke7 7. Nf7 Qe8 8. Nxh8 Nxh5 9. Qe2 Kd8 10. Qc4 Be7 11. Nf7+ Kd7 12. Qe6+ Kc6 13. Qxe4+ Kd7 14. Qe6+ Kc6 15. Ne5+ Kb6 16. Qb3+ Ka6 17. Qa3+ Kb6 18. Nc4+ Kc6 19. Qf3+ Kd7 20. 0-0 Qf7 21. d3 Nc6 22. c3 Ke8 23. Ne3 Ne5 24. Qe2 Nf4 25. Qd1 b6 26. Qb3 Qf8 27. Nd5 Ne2+ 28. Kh1 Qxf5 29. Nxe7 Kxe7 30. Qd1 Nxc1 31. Qxc1 Nxd3 32. Qe3+ Kd7 33. b4 Bb7 1/2-1/2

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2006.05.30"]
[Round "3"]
[White "Bakker, Joop"]
[Black "Zwaan, Gert Jan"]
[Result "1-0"]
[ECO "B24"]
[WhiteElo "1850"]
[BlackElo "1516"]
[PlyCount "71"]
[EventDate "2006.05.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 c5 2. Ne2 Nc6 3. Nbc3 g6 4. g3 Bg7 5. Bg2 Nf6 6. 0-0 0-0 7. d3 a6 8. Be3 d6 9. Qd2 Ng4 10. Bf4 e5 11. Bg5 f6 12. Be3 Kf7 13. Nd5 Be6 14. Nec3 h5 15. f4 Nxe3 16. Nxe3 f5 17. exf5 gxf5 18. fxe5 Bh6 19. Qe2 Nd4 20. Qxh5+ Kg7 21. Ncd5 Bxe3+ 22. Nxe3 Rh8 23. Qd1 Qg5 24. Qe1 dxe5 25. Nc4 e4 26. Nb6 Rae8 27. dxe4 Nxc2 28. Qc3+ Nd4 29. exf5 Bxf5 30. Rae1 Kg6 31. Rxe8 Rxe8 32. Qxc5 Qe3+ 33. Kh1 Qe1 34. Qxd4 Qe6 35. Nd5 Kh7 36. Nf6+ 1-0

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2006.05.23"]
[Round "2"]
[White "Zwaan, Gert Jan"]
[Black "Helfferich, Gert"]
[Result "1-0"]
[ECO "C60"]
[WhiteElo "1516"]
[BlackElo "944"]
[PlyCount "75"]
[EventDate "2006.05.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 Qf6 4. 0-0 d6 5. d3 Bg4 6. Nbd2 Qg6 7. Kh1 0-0-0 8. Bxc6 bxc6 9. c3 d5 10. Re1 Bc5 11. Rf1 dxe4 12. Nxe4 Qxe4 13. dxe4 Rxd1 14. Rxd1 Bxf2 15. Rf1 Bb6 16. Nxe5 Bh5 17. Nxc6 Nf6 18. Ne7+ Kd7 19. Nf5 g6 20. Ng3 Ke6 21. h3 c6 22. Bg5 Nd7 23. Rae1 Bc7 24. Bf4 Bd8 25. Ne2 Nc5 26. Nd4+ Kd7 27. g4 Nd3 28. Re2 g5 29. Bc1 Bg6 30. Rd2 Bxe4+ 31. Nf3 Bc7 32. Rxd3+ Bxd3 33. Rd1 Re8 34. Rxd3+ Kc8 35. Re3 Rd8 36. Kg2 Bf4 37. Re1 Bc7 38. Bxg5 1-0

[Event "Leiden SB-ch"]
[Site "Leiden"]
[Date "2006.05.16"]
[Round "1"]
[White "Leeuwenburgh, Evert"]
[Black "Zwaan, Gert Jan"]
[Result "1-0"]
[ECO "B74"]
[WhiteElo "1970"]
[BlackElo "1516"]
[PlyCount "67"]
[EventDate "2006.05.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be2 Bg7 7. Be3 0-0 8. 0-0 Nc6 9. Nb3 a6 10. a4 Bd7 11. a5 Ne5 12. f3 Bc6 13. Nd5 Nxd5 14. exd5 Be8 15. Qd2 Qc8 16. c3 Nc4 17. Bxc4 Qxc4 18. Ra3 Bb5 19. Re1 Qd3 20. Qxd3 Bxd3 21. Nd2 Rfe8 22. Rb3 Reb8 23. Bb6 Bf8 24. Bc7 Re8 25. Rxb7 Bf5 26. Nc4 Bc8 27. Rb4 Bf5 28. Nb6 Ra7 29. Bxd6 e5 30. Bxf8 Kxf8 31. g4 Bd7 32. c4 f6 33. Nxd7+ Rxd7 34. Rb6 1-0

[Event "Leiden SB-chB"]
[Site "Leiden"]
[Date "2004.07.07"]
[Round "7"]
[White "Zwaan, Gert Jan"]
[Black "Jansen, Bert"]
[Result "1/2-1/2"]
[ECO "A00"]
[BlackElo "1540"]
[PlyCount "80"]
[EventDate "2004.05.19"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. a3 e5 2. b4 d6 3. Bb2 Nf6 4. e3 g6 5. h3 Bg7 6. g4 0-0 7. Bg2 Re8 8. d3 c6 9. Nd2 d5 10. Rb1 a5 11. Bf3 e4 12. dxe4 dxe4 13. Bg2 axb4 14. axb4 Ra4 15. g5 Nh5 16. Bxg7 Nxg7 17. Nxe4 Qxd1+ 18. Rxd1 Nh5 19. c3 Ra3 20. h4 Bf5 21. Nd6 Rd8 22. Nxb7 Rxd1+ 23. Kxd1 Rxc3 24. Na5 Rc2 25. Bf3 Rb2 26. Nxc6 Nxc6 27. Bxc6 Rxb4 28. Bf3 Be6 29. Ne2 Ng7 30. Nd4 Rb1+ 31. Kc2 Rxh1 32. Bxh1 Nf5 33. Nxf5 Bxf5+ 34. e4 Be6 35. Kc3 Kg7 36. e5 h5 37. Kd4 Kf8 38. Bd5 Bd7 39. f4 Ke7 40. Kc5 Bf5 1/2-1/2

[Event "Leiden SB-chB"]
[Site "Leiden"]
[Date "2004.06.23"]
[Round "5"]
[White "Zwaan, Gert Jan"]
[Black "Van der Maat, Niek"]
[Result "0-1"]
[ECO "B10"]
[BlackElo "1811"]
[PlyCount "84"]
[EventDate "2004.05.19"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 c6 2. Nf3 d5 3. e5 Bg4 4. d4 e6 5. Be2 c5 6. h3 Bxf3 7. Bxf3 cxd4 8. 0-0 Nc6 9. Re1 Nge7 10. Bg5 Qb6 11. b3 Ng6 12. Bh5 Rc8 13. Bxg6 hxg6 14. a3 a5 15. Qd3 Bc5 16. Re2 Na7 17. Nd2 Qb5 18. Qf3 Nc6 19. Kh2 Rh5 20. Qg4 Rxg5 21. Qxg5 Qxe2 22. Nf3 Be7 23. Qf4 Qxf2 24. Rc1 Qe3 25. Qxe3 dxe3 26. c3 Nxe5 27. Nd4 Nc6 28. Nb5 Kf8 29. Re1 Bg5 30. g3 e5 31. h4 Bh6 32. Kg2 d4 33. cxd4 exd4 34. Nd6 Rc7 35. Nc4 Re7 36. Kf3 Ne5+ 37. Nxe5 Rxe5 38. g4 g5 39. b4 gxh4 40. Rh1 e2 41. Rxh4 e1Q 42. g5 Qxh4 0-1

[Event "Leiden SB-chB"]
[Site "Leiden"]
[Date "2004.06.09"]
[Round "4"]
[White "Kettenis, John"]
[Black "Zwaan, Gert Jan"]
[Result "1/2-1/2"]
[ECO "E91"]
[WhiteElo "1556"]
[PlyCount "76"]
[EventDate "2004.05.19"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 d6 3. Nf3 g6 4. Nc3 Bg7 5. e4 0-0 6. Be2 c5 7. d5 e6 8. h3 a6 9. a4 e5 10. 0-0 Ne8 11. Bd2 f5 12. Qc1 f4 13. Ne1 g5 14. f3 h6 15. Nd3 Bf6 16. b4 b6 17. bxc5 bxc5 18. a5 Rf7 19. Na4 Raa7 20. Qc2 Nd7 21. Rab1 Rb7 22. Rxb7 Bxb7 23. Rb1 Nf8 24. Nb6 Ng7 25. Nf2 h5 26. Rb3 h4 27. Ng4 Kh7 28. Qb1 Nh5 29. Nxf6+ Nxf6 30. Na4 Qc7 31. Rb6 Kg8 32. Bd1 Nh5 33. Nc3 Bc8 34. Ba4 Nd7 35. Bxd7 Rxd7 36. Na4 Rf7 37. Rb8 Kg7 38. Qb6 Qd7 1/2-1/2

[Event "Leiden SB-chB"]
[Site "Leiden"]
[Date "2004.06.09"]
[Round "6"]
[White "Van Dijk, Rens"]
[Black "Zwaan, Gert Jan"]
[Result "1/2-1/2"]
[ECO "C00"]
[WhiteElo "1500"]
[PlyCount "74"]
[EventDate "2004.05.19"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 e6 2. Nf3 d5 3. exd5 exd5 4. Be2 Nf6 5. 0-0 c5 6. Bb5+ Nc6 7. Re1+ Be7 8. Ne5 Bd7 9. Bxc6 Bxc6 10. d4 0-0 11. Bg5 Re8 12. Nc3 Qb6 13. Nxc6 bxc6 14. Na4 Qa5 15. Bxf6 gxf6 16. c3 Kh8 17. Nxc5 Bxc5 18. Rxe8+ Rxe8 19. b4 Bxb4 20. cxb4 Qxb4 21. Rb1 Qe7 22. Rc1 Qe2 23. a4 a5 24. g3 Kg7 25. Qxe2 Rxe2 26. Rxc6 Ra2 27. Rc5 Rxa4 28. Rxd5 Ra1+ 29. Kg2 a4 30. Ra5 a3 31. d5 a2 32. Kf3 Rd1 33. Rxa2 Rxd5 34. h4 h6 35. Kg2 Rd4 36. f4 Rd5 37. Kh3 h5 1/2-1/2

[Event "Leiden SB-chB"]
[Site "Leiden"]
[Date "2004.06.02"]
[Round "3"]
[White "Zwaan, Gert Jan"]
[Black "De Vreede, Henk"]
[Result "1-0"]
[ECO "C41"]
[BlackElo "1485"]
[PlyCount "87"]
[EventDate "2004.05.19"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 d6 3. Nc3 Be7 4. d4 exd4 5. Nxd4 Bf6 6. f4 c5 7. Ndb5 Bxc3+ 8. bxc3 Ke7 9. e5 dxe5 10. Qxd8+ Kxd8 11. fxe5 Be6 12. Bf4 Ne7 13. Rd1+ Nd7 14. Be2 a6 15. Nd6 Kc7 16. 0-0 Ng6 17. Bc4 Ngxe5 18. Bxe6 fxe6 19. Nf7 Rhf8 20. Bxe5+ Nxe5 21. Nxe5 Rxf1+ 22. Rxf1 Kd6 23. Nc4+ Ke7 24. Re1 Rd8 25. g3 b5 26. Ne3 c4 27. a3 h6 28. Kf2 Rf8+ 29. Kg2 Rd8 30. Re2 Rf8 31. h4 Rd8 32. g4 g6 33. Kg3 Rf8 34. Ng2 Rd8 35. Re1 g5 36. h5 Rd2 37. Ne3 Rd8 38. Nf5+ Kf6 39. Nd4 Rd6 40. Rf1+ Ke7 41. Re1 Kf6 42. Rf1+ Ke7 43. Kf3 Rd8 44. Nc6+ 1-0

[Event "Leiden SB-chB"]
[Site "Leiden"]
[Date "2004.05.26"]
[Round "2"]
[White "Molsbergen, Chris"]
[Black "Zwaan, Gert Jan"]
[Result "1-0"]
[ECO "B90"]
[WhiteElo "1508"]
[PlyCount "98"]
[EventDate "2004.05.19"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 a6 5. Be3 Nf6 6. Nc3 e5 7. Nb3 Nc6 8. Be2 Be6 9. f3 Qc7 10. 0-0 Be7 11. a4 0-0 12. Qd2 Rad8 13. a5 Bxb3 14. Bb6 Qc8 15. Bxd8 Qxd8 16. cxb3 Nxa5 17. Bd1 Qb6+ 18. Qf2 Qxf2+ 19. Rxf2 Bd8 20. Rd2 Bb6+ 21. Kf1 Be3 22. Rd3 Bb6 23. Rxd6 Bc7 24. Rd3 b5 25. Nd5 Nxd5 26. exd5 Rd8 27. Rc3 Bb6 28. Rd3 h6 29. b4 Nc4 30. Rxa6 Nxb2 31. Rxb6 Nxd3 32. Rxb5 f5 33. Be2 e4 34. Bxd3 exd3 35. Ke1 Kf7 36. Kd2 Kf6 37. Kxd3 Ke5 38. Kc4 h5 39. Rc5 h4 40. b5 Rd6 41. Rc7 Rg6 42. d6 Kxd6 43. Rc6+ Ke5 44. Rxg6 f4 45. b6 h3 46. gxh3 Kf5 47. Rg4 g5 48. b7 Kg6 49. b8Q Kf5 1-0

[Event "Leiden SB-chB"]
[Site "Leiden"]
[Date "2004.05.19"]
[Round "1"]
[White "Zwaan, Gert Jan"]
[Black "Brouwer, Pieter"]
[Result "0-1"]
[ECO "C50"]
[BlackElo "1569"]
[PlyCount "64"]
[EventDate "2004.05.19"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "NED"]
[SourceTitle "EXT 2012"]
[Source "ChessBase"]
[SourceDate "2011.11.24"]
[SourceVersion "1"]
[SourceVersionDate "2011.11.24"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 d6 4. d3 Na5 5. Bb5+ c6 6. Ba4 b5 7. Bb3 Be7 8. c3 Nxb3 9. Qxb3 Be6 10. Qd1 Nf6 11. h3 0-0 12. Nbd2 Nd7 13. Nf1 f5 14. Qe2 fxe4 15. dxe4 Bc4 16. Qd1 Nc5 17. Kd2 Nxe4+ 18. Ke1 Bh4 19. Be3 Qe7 20. Qc2 Nc5 21. Nxh4 Qxh4 22. Ng3 Rad8 23. b3 Bd3 24. Qd2 h6 25. b4 Be4 26. bxc5 dxc5 27. Qb2 c4 28. Rg1 Rd3 29. Qe2 Rfd8 30. Rc1 R8d7 31. Bxh6 Qxh6 32. Nxe4 Qxc1+ 0-1

