[Event "NED corr"]
[Site "Netherlands"]
[Date "1999.??.??"]
[Round "?"]
[White "Sieswerda, S."]
[Black "Dudeman"]
[Result "0-1"]
[ECO "A40"]
[PlyCount "62"]
[EventDate "1999.??.??"]
[EventType "game (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr 2002"]
[Source "ChessBase"]
[SourceDate "2002.05.23"]
[SourceVersion "1"]
[SourceVersionDate "2002.05.23"]
[SourceQuality "1"]

1. d4 e6 2. c4 b6 3. Nc3 Bb7 4. e4 Bb4 5. Bd3 f5 6. d5 fxe4 7. Bxe4 Nf6 8. Bg5 Bxc3+ 9. bxc3 0-0 10. Nf3 Qe8 11. Bxf6 exd5 12. Bd4 Qxe4+ 13. Be3 Qxc4 14. Qc2 Re8 15. 0-0-0 Qe4 16. Qd2 Qg6 17. Bd4 c5 18. Be3 d6 19. h4 d4 20. Bf4 dxc3 21. Qxc3 d5 22. Rhe1 Rxe1 23. Rxe1 Nc6 24. Ne5 Qxg2 25. Nf3 Nb4 26. Qe3 Qg6 27. Re2 d4 28. Nxd4 cxd4 29. Qb3+ Nd5 30. Be5 Rc8+ 31. Kd2 Rc3 0-1

[Event "NED Z98 corr"]
[Site "Netherlands"]
[Date "1998.??.??"]
[Round "?"]
[White "Mostertman, Loek G"]
[Black "Sieswerda, S."]
[Result "1-0"]
[ECO "B22"]
[PlyCount "57"]
[EventDate "1998.??.??"]
[EventType "team (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr 2002"]
[Source "ChessBase"]
[SourceDate "2002.05.23"]
[SourceVersion "1"]
[SourceVersionDate "2002.05.23"]
[SourceQuality "1"]

1. e4 c5 2. d4 cxd4 3. c3 Nc6 4. cxd4 e6 5. d5 exd5 6. exd5 Bb4+ 7. Nc3 Qe7+ 8. Be3 Ne5 9. Qd4 Nf6 10. 0-0-0 Bxc3 11. bxc3 0-0 12. h3 Ng6 13. Nf3 Re8 14. Bd3 Ne5 15. Nxe5 Qxe5 16. Qxe5 Rxe5 17. c4 b6 18. Bd4 Rg5 19. g4 Ba6 20. f4 Rg6 21. Kb2 b5 22. Bxg6 fxg6 23. Bxf6 gxf6 24. c5 b4 25. Rd4 Rb8 26. Kb3 Bb7 27. Ka4 a6 28. Rxb4 Bc6+ 29. dxc6 1-0

[Event "NED-Cup corr"]
[Site "Netherlands"]
[Date "1998.??.??"]
[Round "?"]
[White "Nieuweboer, Mark"]
[Black "Sieswerda, S."]
[Result "1-0"]
[ECO "B89"]
[PlyCount "51"]
[EventDate "1998.??.??"]
[EventType "tourn (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr 2000"]
[Source "ChessBase"]
[SourceDate "2000.04.19"]
[SourceVersion "1"]
[SourceVersionDate "2000.04.19"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 d6 6. Bc4 e6 7. Be3 Be7 8. Qe2 Bd7 9. 0-0-0 0-0 10. Bb3 a6 11. f4 Rc8 12. g4 e5 13. Nf5 Na5 14. g5 Nxb3+ 15. axb3 Nxe4 16. Nxe7+ Qxe7 17. Nxe4 exf4 18. Bxf4 Bf5 19. Rhe1 Rfe8 20. Rd4 Qe6 21. Bxd6 h6 22. h4 Kh8 23. Bf4 Bg4 24. Qe3 h5 25. Nd6 Qd7 26. Nxe8 1-0

[Event "NED-Cup corr"]
[Site "Netherlands"]
[Date "1997.??.??"]
[Round "?"]
[White "De Boer, Willem J"]
[Black "Sieswerda, S."]
[Result "1-0"]
[ECO "C57"]
[PlyCount "61"]
[EventDate "1997.??.??"]
[EventType "team (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr 2000"]
[Source "ChessBase"]
[SourceDate "2000.04.19"]
[SourceVersion "1"]
[SourceVersionDate "2000.04.19"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 d5 5. exd5 Nxd5 6. d4 Be7 7. Nxf7 Kxf7 8. Qf3+ Ke8 9. Bxd5 Nxd4 10. Qh5+ Kd7 11. Be4 Bf6 12. c3 Ne6 13. 0-0 Ke7 14. b3 Qe8 15. Qf3 Rb8 16. Rd1 c6 17. Qd3 Qd8 18. Ba3+ c5 19. Qxd8+ Rxd8 20. Rxd8 Kxd8 21. Bxh7 Ng5 22. Bg6 b6 23. Nd2 Bb7 24. b4 e4 25. bxc5 Bxc3 26. Rd1 Kc7 27. cxb6+ Kxb6 28. Rb1+ Ka6 29. Nb3 Ne6 30. Bf5 Nd8 31. Bd6 1-0

[Event "NED-Cup corr"]
[Site "Netherlands"]
[Date "1993.??.??"]
[Round "?"]
[White "Donk, B."]
[Black "Sieswerda, S."]
[Result "1-0"]
[ECO "B07"]
[PlyCount "95"]
[EventDate "1993.??.??"]
[EventType "tourn (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr Nr. 1"]
[Source "ChessBase"]
[SourceDate "1997.09.01"]
[SourceVersion "2"]
[SourceVersionDate "2000.04.19"]
[SourceQuality "1"]

1. e4 d6 2. d4 Nf6 3. Nc3 g6 4. Bc4 Bg7 5. Qe2 0-0 6. e5 dxe5 7. dxe5 Ne8 8. Bg5 c6 9. Rd1 Qc7 10. f4 Kh8 11. Nf3 f6 12. Bh4 Bg4 13. 0-0 Nd7 14. exf6 Nexf6 15. h3 Bxf3 16. Rxf3 e5 17. f5 Nh5 18. Kh1 Ndf6 19. Bxf6 Nxf6 20. fxg6 Rad8 21. Rdf1 Qd6 22. Rd3 Qe7 23. gxh7 Nxh7 24. Rxd8 Qxd8 25. Rxf8+ Qxf8 26. Qh5 Qf4 27. Bd3 Bh6 28. Ne2 Qf1+ 29. Ng1 Qf6 30. Nf3 Qf4 31. Qxe5+ Qxe5 32. Nxe5 Kg7 33. Bxh7 Kxh7 34. b3 Kg7 35. g4 Kf6 36. Nf3 Ke6 37. Kg2 Bf4 38. Nd4+ Ke5 39. Kf3 Bg5 40. Nf5 Bf6 41. h4 Bd8 42. Kg3 Bc7 43. h5 Ke4+ 44. Kh3 Ke5 45. h6 Bd8 46. h7 Bf6 47. Ne7 Ke6 48. Ng6 1-0

[Event "NED-ch M corr"]
[Site "Netherlands"]
[Date "1993.??.??"]
[Round "?"]
[White "Sieswerda, S."]
[Black "Legemaat, Gert"]
[Result "0-1"]
[ECO "D94"]
[PlyCount "56"]
[EventDate "1993.??.??"]
[EventType "tourn (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr Nr. 1"]
[Source "ChessBase"]
[SourceDate "1997.09.01"]
[SourceVersion "2"]
[SourceVersionDate "2000.04.19"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. Nf3 Bg7 5. e3 0-0 6. Qc2 c5 7. cxd5 cxd4 8. exd4 Nxd5 9. Nxd5 Qxd5 10. Bc4 Qd6 11. 0-0 Nc6 12. Be3 Bg4 13. Be2 Rac8 14. Qe4 f5 15. Bc4+ Kh8 16. Qe6 Bxf3 17. gxf3 f4 18. Bd2 Nxd4 19. Qxd6 exd6 20. Bd5 Rc5 21. Be4 Rg5+ 22. Kh1 d5 23. Bd3 Nxf3 24. Bb4 Re8 25. Bb5 Re4 26. Ba3 Nxh2 27. Rfe1 Ng4 28. f3 Rh5+ 0-1

[Event "NED-ch M corr"]
[Site "Netherlands"]
[Date "1993.??.??"]
[Round "?"]
[White "Sieswerda, S."]
[Black "Van der Wouden, GLNM"]
[Result "0-1"]
[ECO "E94"]
[PlyCount "42"]
[EventDate "1993.??.??"]
[EventType "tourn (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr Nr. 1"]
[Source "ChessBase"]
[SourceDate "1997.09.01"]
[SourceVersion "2"]
[SourceVersionDate "2000.04.19"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 0-0 6. Be2 e5 7. dxe5 dxe5 8. 0-0 Na6 9. Bg5 Qxd1 10. Rfxd1 c6 11. Rd6 Be6 12. Rad1 h6 13. Bh4 g5 14. Bg3 Nc5 15. Bxe5 Nfxe4 16. Bxg7 Kxg7 17. Nxe4 Nxe4 18. R6d4 Nf6 19. Ne5 Rfe8 20. Ng4 Bxg4 21. Bxg4 c5 0-1

[Event "NED jub25 q corr9193"]
[Site "Netherlands"]
[Date "1991.??.??"]
[Round "?"]
[White "Bes, Rob NM"]
[Black "Sieswerda, S."]
[Result "1-0"]
[ECO "C91"]
[PlyCount "43"]
[EventDate "1991.??.??"]
[EventType "tourn (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr Nr. 1"]
[Source "ChessBase"]
[SourceDate "1997.09.01"]
[SourceVersion "2"]
[SourceVersionDate "2000.04.19"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 b5 5. Bb3 Nf6 6. 0-0 Be7 7. Re1 0-0 8. d4 d6 9. c3 Bg4 10. Be3 Rc8 11. Nbd2 exd4 12. cxd4 Nb4 13. h3 Bh5 14. Nf1 Nxe4 15. a3 Nc6 16. Bd5 Nxf2 17. Bxf2 Qd7 18. Bxc6 Qxc6 19. Rxe7 d5 20. Re5 Bg6 21. Rc1 Qd6 22. Ne3 1-0

[Event "NED-ch M corr"]
[Site "Netherlands"]
[Date "1991.??.??"]
[Round "?"]
[White "De Boer, Pieter"]
[Black "Sieswerda, S."]
[Result "1-0"]
[ECO "D00"]
[PlyCount "85"]
[EventDate "1991.??.??"]
[EventType "tourn (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr Nr. 1"]
[Source "ChessBase"]
[SourceDate "1997.09.01"]
[SourceVersion "2"]
[SourceVersionDate "2000.04.19"]
[SourceQuality "1"]

1. d4 Nf6 2. e3 d5 3. Bd3 e6 4. Nd2 Nbd7 5. f4 c5 6. c3 Bd6 7. Nh3 c4 8. Bc2 b5 9. Nf2 Bb7 10. e4 dxe4 11. Ndxe4 Be7 12. 0-0 Qc7 13. Nxf6+ Nxf6 14. Ng4 Nxg4 15. Qxg4 Bf6 16. f5 Bd5 17. fxe6 fxe6 18. a4 b4 19. Bf4 Qc6 20. Be5 Bxe5 21. Qh5+ g6 22. Qxe5 0-0-0 23. cxb4 Bxg2 24. Rf7 Bh1 25. Be4 Bxe4 26. b5 Qb6 27. Qxe4 Qxd4+ 28. Qxd4 Rxd4 29. Rxa7 Rhd8 30. Rxh7 Rd1+ 31. Rxd1 Rxd1+ 32. Kf2 Rd2+ 33. Ke3 Rxb2 34. Kd4 Ra2 35. Ra7 Rxh2 36. Kxc4 g5 37. b6 Kb8 38. Kb5 Rh8 39. Rg7 g4 40. a5 Rh5+ 41. Kc6 Rh8 42. a6 Rc8+ 43. Kb5 1-0

[Event "NED jub25 q corr9193"]
[Site "Netherlands"]
[Date "1991.??.??"]
[Round "?"]
[White "Vleer, H."]
[Black "Sieswerda, S."]
[Result "1-0"]
[ECO "D53"]
[PlyCount "71"]
[EventDate "1991.??.??"]
[EventType "tourn (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr Nr. 1"]
[Source "ChessBase"]
[SourceDate "1997.09.01"]
[SourceVersion "2"]
[SourceVersionDate "2000.04.19"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 e6 3. Nc3 d5 4. Nf3 Nc6 5. Bg5 Be7 6. e3 0-0 7. Bd3 Re8 8. 0-0 dxc4 9. Bxc4 Nd5 10. Bxe7 Ncxe7 11. Rc1 Bd7 12. Ne5 Bc6 13. Qh5 Rf8 14. Nxc6 bxc6 15. Ne4 Rb8 16. Bb3 Rb5 17. Qe2 Nb6 18. Nc5 Nd7 19. Nd3 Nf6 20. Ne5 Rb6 21. Rfd1 Qa8 22. Ba4 Nfd5 23. Nd7 Qb7 24. Nxf8 Rxb2 25. Qd3 Kxf8 26. Qxh7 c5 27. dxc5 Ng6 28. Bc2 Nc3 29. Bxg6 Nxd1 30. Be4 Qb4 31. Rxd1 Rd2 32. Qh8+ Ke7 33. Rxd2 Qxd2 34. g3 g6 35. c6 Qxa2 36. Qe5 1-0

[Event "NED corr"]
[Site "Netherlands"]
[Date "1989.??.??"]
[Round "?"]
[White "Sieswerda, S."]
[Black "Koegeler, Aart"]
[Result "1-0"]
[ECO "E54"]
[PlyCount "43"]
[EventDate "1989.??.??"]
[EventType "tourn (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr Nr. 1"]
[Source "ChessBase"]
[SourceDate "1997.09.01"]
[SourceVersion "2"]
[SourceVersionDate "2000.04.19"]
[SourceQuality "1"]

1. d4 d5 2. Nf3 Nf6 3. c4 e6 4. Nc3 Bb4 5. e3 0-0 6. Bd3 dxc4 7. Bxc4 c5 8. 0-0 cxd4 9. exd4 Qc7 10. Ne5 Nc6 11. Nb5 Qb8 12. Bf4 a6 13. Nd3 e5 14. dxe5 axb5 15. exf6 Bd6 16. fxg7 Rd8 17. Bxd6 Qxd6 18. Bxb5 Bf5 19. Re1 Bxd3 20. Bxd3 Qxd3 21. Re8+ Kxg7 22. Qxd3 1-0

[Event "NED-ch H corr"]
[Site "Netherlands"]
[Date "1988.??.??"]
[Round "?"]
[White "De Wit"]
[Black "Sieswerda, S."]
[Result "1-0"]
[ECO "B09"]
[PlyCount "83"]
[EventDate "1988.??.??"]
[EventType "tourn (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr Nr. 1"]
[Source "ChessBase"]
[SourceDate "1997.09.01"]
[SourceVersion "2"]
[SourceVersionDate "2000.04.19"]
[SourceQuality "1"]

1. e4 d6 2. d4 g6 3. Nc3 Bg7 4. f4 e6 5. Nf3 Nf6 6. Be2 a6 7. a4 0-0 8. 0-0 c6 9. e5 Nd5 10. Ne4 dxe5 11. fxe5 Nd7 12. Kh1 f6 13. c4 Nc7 14. exf6 Nxf6 15. Bg5 Nce8 16. Ne5 Qc7 17. Qd3 Nxe4 18. Rxf8+ Kxf8 19. Qxe4 Kg8 20. c5 Bxe5 21. dxe5 Ng7 22. Rd1 Bd7 23. Qd4 Be8 24. Bc4 Qf7 25. Qd6 h6 26. Bxh6 Nf5 27. Qxe6 Kh7 28. Qxf7+ Bxf7 29. Rd7 Kxh6 30. Bxf7 Kg5 31. e6 Kf6 32. Rxb7 Rd8 33. Rd7 Rb8 34. g4 Ne3 35. g5+ Kxg5 36. e7 Rxb2 37. h4+ Kf4 38. e8Q Nf5 39. Qd8 Ng3+ 40. Kg1 Ne4 41. Rd1 Re2 42. Bxg6 1-0

[Event "NED corr"]
[Site "Netherlands"]
[Date "1988.??.??"]
[Round "?"]
[White "Fokkens, J."]
[Black "Sieswerda, S."]
[Result "1-0"]
[ECO "B40"]
[PlyCount "57"]
[EventDate "1988.??.??"]
[EventType "team (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr Nr. 1"]
[Source "ChessBase"]
[SourceDate "1997.09.01"]
[SourceVersion "2"]
[SourceVersionDate "2000.04.19"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 Bb4 6. e5 Nd5 7. Qg4 Bxc3+ 8. bxc3 Qc7 9. Qg3 Qxc3+ 10. Qxc3 Nxc3 11. Bd2 Nd5 12. c4 Nc7 13. Bb4 Nc6 14. Nxc6 bxc6 15. Bd6 Kd8 16. Rb1 a5 17. Kd2 Ba6 18. Bd3 Ne8 19. Rb6 Nxd6 20. exd6 f5 21. Rhb1 Kc8 22. c5 Bxd3 23. Kxd3 e5 24. Rb7 Rf8 25. Rc7+ Kd8 26. Rbb7 Rf7 27. Rxc6 Rc8 28. Ra6 g5 29. c6 1-0

[Event "NED-chS corr"]
[Site "Netherlands"]
[Date "1986.??.??"]
[Round "?"]
[White "Blokland, JG."]
[Black "Sieswerda, S."]
[Result "1/2-1/2"]
[ECO "B08"]
[PlyCount "98"]
[EventDate "1986.??.??"]
[EventType "tourn (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr Nr. 1"]
[Source "ChessBase"]
[SourceDate "1997.09.01"]
[SourceVersion "2"]
[SourceVersionDate "2000.04.19"]
[SourceQuality "1"]

1. e4 g6 2. d4 d6 3. Nc3 Nf6 4. Nf3 Bg7 5. Be2 0-0 6. 0-0 a6 7. a4 Nbd7 8. e5 dxe5 9. dxe5 Ng4 10. e6 Nde5 11. Ng5 Qxd1 12. Rxd1 f6 13. Nge4 Bxe6 14. f4 Nc6 15. Nc5 Bf5 16. Bc4+ Kh8 17. Ne6 Bxe6 18. Bxe6 f5 19. h3 Bd4+ 20. Kf1 Nf2 21. Rd2 Bxc3 22. bxc3 Ne4 23. Rd1 Rf6 24. Bb3 Rd6 25. Ba3 Rd2 26. Rxd2 Nxd2+ 27. Ke2 Nxb3 28. cxb3 Rd8 29. Rd1 Rxd1 30. Kxd1 e5 31. fxe5 Nxe5 32. Bc5 Kg8 33. Be3 Kf7 34. Bf4 Ke6 35. Ke2 c6 36. a5 Kd5 37. Ke3 Nd7 38. h4 Nf6 39. Kd3 Nh5 40. Bc7 h6 41. c4+ Ke6 42. Kd4 Nf6 43. Bf4 h5 44. b4 Nd7 45. Bc7 Nc5 46. Bh2 Ne4 47. Bf4 Ke7 48. Ke5 Kf7 49. Be3 Ke7 1/2-1/2

[Event "NED-ch H corr"]
[Site "Netherlands"]
[Date "1984.??.??"]
[Round "?"]
[White "De Vos"]
[Black "Sieswerda, S."]
[Result "1-0"]
[ECO "A43"]
[PlyCount "97"]
[EventDate "1984.??.??"]
[EventType "tourn (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr Nr. 1"]
[Source "ChessBase"]
[SourceDate "1997.09.01"]
[SourceVersion "2"]
[SourceVersionDate "2000.04.19"]
[SourceQuality "1"]

1. e4 g6 2. d4 Bg7 3. Nc3 c5 4. d5 d6 5. Be2 Nf6 6. Bf4 Nbd7 7. Qd2 0-0 8. Nf3 a6 9. a4 Qc7 10. h3 Ne8 11. Bh6 Ndf6 12. g4 e6 13. Bxg7 Nxg7 14. g5 Nfh5 15. Nh2 f5 16. gxf6 Nxf6 17. Ng4 Nfh5 18. Bc4 Nf4 19. dxe6 Bxe6 20. Nd5 Nxd5 21. Bxd5 Qe7 22. Ra3 Rae8 23. Kd1 Kh8 24. Re1 Bxg4+ 25. hxg4 Qd7 26. Rg1 Ne6 27. a5 Nd4 28. f4 Qg7 29. Kc1 Ne6 30. Rf1 Nc7 31. Rb3 Nxd5 32. Qxd5 Qe7 33. Rxb7 Qxe4 34. Qxe4 Rxe4 35. Rh1 Rfxf4 36. Rhxh7+ Kg8 37. Rbg7+ Kf8 38. Rd7 Kg8 39. Rhg7+ Kf8 40. Rxg6 Rf2 41. Rgxd6 Re1+ 42. Rd1 Re4 43. Ra7 Rf6 44. Rd8+ Re8 45. Rxe8+ Kxe8 46. Rc7 Rg6 47. Rxc5 Kd7 48. g5 Kd6 49. b4 1-0

[Event "EU-chT Railways USIC 10th"]
[Site "Boras"]
[Date "1980.07.26"]
[Round "7.6"]
[White "Eriklintsev, Vladimir"]
[Black "Sieswerda, S."]
[Result "1-0"]
[ECO "B07"]
[PlyCount "57"]
[EventDate "1980.07.20"]
[EventType "team"]
[EventRounds "7"]
[EventCountry "SWE"]
[SourceTitle "EXT 2023"]
[Source "ChessBase"]
[SourceDate "2022.10.05"]
[SourceVersion "1"]
[SourceVersionDate "2022.10.05"]
[SourceQuality "1"]
[WhiteTeam "Soviet Union USIC"]
[BlackTeam "Netherlands USIC"]
[WhiteTeamCountry "URS"]
[BlackTeamCountry "NED"]

1. e4 d6 2. d4 Nf6 3. Nc3 e6 4. f4 Be7 5. Nf3 a6 6. Bd3 c6 7. 0-0 Nbd7 8. e5 dxe5 9. fxe5 Nd5 10. Nxd5 cxd5 11. c3 Nf8 12. Be3 Bd7 13. Qd2 h6 14. Qf2 f5 15. exf6 Bxf6 16. Ne5 Bb5 17. Bxb5+ axb5 18. Qg3 Qe7 19. a3 Bxe5 20. Qxe5 Nd7 21. Qh5+ Kd8 22. Rf7 Qe8 23. Raf1 Nf6 24. Qg6 Rg8 25. Bxh6 gxh6 26. Qxf6+ Kc8 27. Rf8 Rxf8 28. Qxf8 Kd7 29. Rf7+ 1-0

[Event "EU-chT Railways USIC 10th"]
[Site "Boras"]
[Date "1980.07.25"]
[Round "6.6"]
[White "Dunn, Walter"]
[Black "Sieswerda, S."]
[Result "1-0"]
[ECO "A05"]
[PlyCount "45"]
[EventDate "1980.07.20"]
[EventType "team"]
[EventRounds "7"]
[EventCountry "SWE"]
[SourceTitle "EXT 2023"]
[Source "ChessBase"]
[SourceDate "2022.10.05"]
[SourceVersion "1"]
[SourceVersionDate "2022.10.05"]
[SourceQuality "1"]
[WhiteTeam "England USIC"]
[BlackTeam "Netherlands USIC"]
[WhiteTeamCountry "ENG"]
[BlackTeamCountry "NED"]

1. Nf3 Nf6 2. b3 e6 3. Bb2 Be7 4. g3 d5 5. e3 0-0 6. Bg2 Nbd7 7. 0-0 c6 8. d3 Qc7 9. Nbd2 Re8 10. d4 Bd6 11. c4 b6 12. Rc1 Bb7 13. Rc2 Qb8 14. Qa1 c5 15. Ne5 Bc7 16. Nxd7 Nxd7 17. cxd5 cxd4 18. dxe6 Rxe6 19. Bh3 Rc6 20. Rxc6 Bxc6 21. Bxd4 f6 22. Rc1 Ne5 23. Qc3 1-0

[Event "EU-chT Railways USIC 10th"]
[Site "Boras"]
[Date "1980.07.22"]
[Round "3.6"]
[White "Sieswerda, S."]
[Black "Szalajdewicz, Janusz"]
[Result "0-1"]
[ECO "E54"]
[BlackElo "2245"]
[PlyCount "132"]
[EventDate "1980.07.20"]
[EventType "team"]
[EventRounds "7"]
[EventCountry "SWE"]
[SourceTitle "EXT 2023"]
[Source "ChessBase"]
[SourceDate "2022.10.05"]
[SourceVersion "1"]
[SourceVersionDate "2022.10.05"]
[SourceQuality "1"]
[WhiteTeam "Netherlands USIC"]
[BlackTeam "Poland USIC"]
[WhiteTeamCountry "NED"]
[BlackTeamCountry "POL"]

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 0-0 5. Bd3 c5 6. Nf3 d5 7. 0-0 cxd4 8. exd4 dxc4 9. Bxc4 b6 10. Be2 Bb7 11. a3 Be7 12. Re1 Na6 13. Be3 Nc7 14. Rc1 Ncd5 15. Bd2 Nxc3 16. Bxc3 Nd5 17. Bd2 Bf6 18. Bc4 Rc8 19. Qe2 Nc7 20. Red1 a6 21. Bf4 b5 22. Bb3 Qe7 23. Be5 Nd5 24. Qd2 Rcd8 25. Bxd5 Bxd5 26. Rc7 Rd7 27. Rxd7 Qxd7 28. Bxf6 gxf6 29. Qf4 Qe7 30. Rc1 Bxf3 31. Qxf3 Rd8 32. Qg4+ Kh8 33. h3 Qd6 34. Qh5 Qf4 35. Rc3 Rxd4 36. Rc8+ Kg7 37. g3 Qe4 38. Rc7 Qg6 39. Qxg6+ hxg6 40. Rc6 Ra4 41. Kf1 f5 42. Ke2 e5 43. Kf3 f4 44. g4 g5 45. Rc5 Kf6 46. Rc6+ Ke7 47. Rc7+ Ke6 48. Rc6+ Kd7 49. Rf6 Ke7 50. Rc6 f6 51. Rc7+ Kd6 52. Rf7 e4+ 53. Ke2 Ke6 54. Rc7 Rd4 55. Rc6+ Rd6 56. Rc5 Kd7 57. Rf5 Ke6 58. h4 Rd5 59. Rxd5 Kxd5 60. h5 Ke6 61. Kd2 Kf7 62. Ke2 Kg7 63. f3 exf3+ 64. Kxf3 a5 65. b3 Kh7 66. Ke4 Kh6 0-1

[Event "EU-chT Railways USIC 10th"]
[Site "Boras"]
[Date "1980.07.22"]
[Round "2.6"]
[White "Weiss, H."]
[Black "Sieswerda, S."]
[Result "1/2-1/2"]
[ECO "B07"]
[PlyCount "88"]
[EventDate "1980.07.20"]
[EventType "team"]
[EventRounds "7"]
[EventCountry "SWE"]
[SourceTitle "EXT 2023"]
[Source "ChessBase"]
[SourceDate "2022.10.05"]
[SourceVersion "1"]
[SourceVersionDate "2022.10.05"]
[SourceQuality "1"]
[WhiteTeam "Austria USIC"]
[BlackTeam "Netherlands USIC"]
[WhiteTeamCountry "AUT"]
[BlackTeamCountry "NED"]

1. e4 d6 2. d4 Nf6 3. Nc3 a6 4. Bg5 Nc6 5. Nf3 Bg4 6. Be2 e6 7. h3 Bxf3 8. Bxf3 Be7 9. Be3 Qd7 10. Qd2 Rb8 11. 0-0 0-0 12. Rad1 Rbd8 13. Qe2 Qc8 14. Kh2 Nb8 15. g3 c6 16. Bg2 Nbd7 17. Nb1 Qc7 18. f4 e5 19. c3 b5 20. Nd2 Rfe8 21. Qf2 Nf8 22. dxe5 dxe5 23. Bb6 Qb8 24. Bxd8 Bxd8 25. f5 Bb6 26. Qe2 h6 27. Bf3 Qa7 28. Nb1 N8d7 29. Na3 c5 30. Nc2 Qb7 31. Ne3 c4 32. Nd5 Bd8 33. Qe3 Qc8 34. Be2 Nc5 35. Nxf6+ Bxf6 36. Rd5 Na4 37. Rb1 Qc7 38. Bd1 Nb6 39. Rc5 Qd6 40. Bf3 Bg5 41. Qf2 Be7 42. Rd5 Nxd5 43. exd5 Bd8 44. Be4 Bb6 1/2-1/2

[Event "NED Cup corr"]
[Site "Netherlands"]
[Date "1980.??.??"]
[Round "?"]
[White "Sieswerda, S."]
[Black "Van der Kooij, Jaap"]
[Result "1-0"]
[ECO "E43"]
[PlyCount "49"]
[EventDate "1980.??.??"]
[EventType "tourn (corr)"]
[EventRounds "10"]
[EventCountry "NED"]
[SourceTitle "Corr Nr. 1"]
[Source "ChessBase"]
[SourceDate "1997.09.01"]
[SourceVersion "2"]
[SourceVersionDate "2000.04.19"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 c5 5. Nf3 b6 6. Bd3 Bb7 7. 0-0 d5 8. a3 Bxc3 9. bxc3 Nbd7 10. Re1 0-0 11. Qe2 Re8 12. Nd2 Ne4 13. Nxe4 dxe4 14. Bc2 Qg5 15. Ba4 Re7 16. Bd1 f5 17. Qh5 Qxh5 18. Bxh5 Nf6 19. Be2 Rc7 20. Rd1 Rd8 21. d5 exd5 22. cxd5 Bxd5 23. c4 Bf7 24. Bb2 Ne8 25. Rxd8 1-0

