| ECO A05 in 1969 play it! zuidema coenraad defeats white's johannessen svei in 82 moves | 1. Nf3 Nf6 2. g3 d5 3. Bg2 e6 4. c4 Be7 5. O-O O-O 6. b3 c5 7. Bb2 Nc6 8. cxd5 Nxd5 9. Nc3 Bf6 10. Qc1 b6 11. Rd1 Ba6 12. d3 Rc8 13. Ne4 Bxb2 14. Qxb2 Qe7 15. Rac1 Rfd8 16. a3 h6 17. Ned2 Qf6 18. Qxf6 gxf6 19. Nc4 Nc7 20. Kf1 Nb5 21. Nfd2 f5 22. f4 Ne7 23. Kf2 Nd4 24. e3 Ndc6 25. Nf3 Rc7 26. Rd2 f6 27. Bf1 b5 28. Nb2 Na5 29. Rdc2 Nxb3 30. Rb1 Na5 31. Nd1 Rdc8 32. Nc3 b4 33. Na4 Nd5 34. Nd2 Bb5 35. Nb2 bxa3 36. Nbc4 Nxc4 37. Nxc4 Nb4 38. Rc3 a2 39. Ra1 Rd8 40. Nb2 c4 41. d4 Nd5 |
| ECO A15 in 1966 play it! zuidema coenraad defeats white's wotulo max arie in 104 moves | 1. c4 Nf6 2. g3 e6 3. Bg2 d5 4. Nf3 Be7 5. O-O O-O 6. Qc2 b6 7. Nc3 Bb7 8. cxd5 Nxd5 9. d4 c5 10. Rd1 cxd4 11. Nxd4 Nxc3 12. bxc3 Qc8 13. Qb3 Bxg2 14. Kxg2 Nc6 15. Nf3 h6 16. Be3 Na5 17. Qb5 Rd8 18. Qh5 Nc4 19. Bd4 Rd5 20. Ne5 Nxe5 21. Bxe5 Qc5 22. Qf3 Rad8 23. Bd4 Qc4 24. e4 R5d7 25. e5 b5 26. a3 a6 27. h4 Qd5 28. Rdb1 Rc8 29. h5 Rc4 30. Qxd5 Rxd5 31. f4 Bc5 32. a4 Bxd4 33. cxd4 Rxa4 34. Rxa4 bxa4 35. Rb4 Ra5 36. Rb1 a3 37. Ra1 Kf8 38. Ra2 Ke7 39. Kf3 Kd7 40. g4 Kc6 41. Ke4 Kb5 42. g5 Kc4 43. g6 fxg6 44. hxg6 Kb3 45. Ra1 Kb2 46. Rf1 a2 47. f5 a1=Q 48. Rxa1 exf5+ 49. Kxf5 Rxa1 50. d5 Rf1+ 51. Ke6 h5 52. d6 h4 |
| ECO A15 in 1969 play it! zuidema coenraad defeats white's barendregt johan in 56 moves | 1. c4 Nf6 2. d4 e6 3. Nc3 Bb4 4. g3 c5 5. d5 b5 6. dxe6 fxe6 7. Bg2 d5 8. cxd5 Nxd5 9. Bd2 Bb7 10. e4 Nf6 11. Nxb5 Qb6 12. Nc3 O-O 13. Nge2 Nc6 14. O-O Rad8 15. Qc1 Ba6 16. Re1 Ne5 17. Nf4 Nfg4 18. Be3 g5 19. Nh5 Nd3 20. Qc2 Nxe1 21. Rxe1 Nxe3 22. Rxe3 Bxc3 23. Qxc3 Rd1+ 24. Re1 Rxe1+ 25. Qxe1 Qxb2 26. e5 Qe2 27. Nf6+ Kh8 28. Qc1 Rd8 |
| ECO A17 in 1960 play it! zuidema coenraad defeats white's tzend donoy in 48 moves | 1. c4 Nf6 2. Nc3 e6 3. d4 Bb4 4. e3 b6 5. Bd3 O-O 6. Ne2 Ba6 7. a3 Bxc3+ 8. Nxc3 c5 9. O-O cxd4 10. exd4 Nc6 11. Be3 d5 12. b3 Rc8 13. Nb5 Bxb5 14. cxb5 Na5 15. Bd2 Nb7 16. Bg5 h6 17. Bh4 Qe7 18. Qf3 Nd6 19. Rfe1 g5 20. Bg3 Nde4 21. Be5 Rc3 22. Bxf6 Qxf6 23. Qe3 Rxd3 24. Qxd3 Qxf2+ |
| ECO A15 in 1962 play it! zuidema coenraad defeats white's markus marcel in 70 moves | 1. c4 Nf6 2. g3 e6 3. Bg2 d5 4. b3 dxc4 5. Nc3 Bc5 6. Nf3 cxb3 7. Qxb3 Nc6 8. Qb5 Nd7 9. Ne4 a6 10. Qc4 Be7 11. Bb2 O-O 12. O-O Nb6 13. Qc2 Nb4 14. Qc3 f6 15. a4 Bd7 16. Qb3 c5 17. d3 Nxa4 18. Rxa4 Bxa4 19. Qxa4 b5 20. Qb3 Qd5 21. Qc3 Rfc8 22. Nfd2 Qd7 23. Ra1 a5 24. Nb3 Nd5 25. Nexc5 Qc6 26. Bxd5 Qxd5 27. e4 Qc6 28. d4 a4 29. Nd2 e5 30. Ba3 exd4 31. Qxd4 Bxc5 32. Bxc5 Qxc5 33. Qd7 Kh8 34. Nf3 Qc3 35. Qd1 Rd8 |
| ECO A15 in 1973 play it! zuidema coenraad defeats white's boersma paul in 84 moves | 1. c4 Nf6 2. Nf3 e6 3. g3 d5 4. Bg2 dxc4 5. Qa4+ Nbd7 6. O-O a6 7. Qxc4 b5 8. Qc6 Rb8 9. Qc2 c5 10. a4 Bb7 11. axb5 axb5 12. d4 Qb6 13. Nbd2 cxd4 14. Nb3 e5 15. Ng5 Bxg2 16. Kxg2 h6 17. Ne4 Qb7 18. f3 Nxe4 19. Na5 Qd5 20. fxe4 Qe6 21. Bd2 Bd6 22. Nb7 O-O 23. Qc6 Rfc8 24. Qxd6 Rxb7 25. Qxe6 fxe6 26. Rfc1 Rbc7 27. Rxc7 Rxc7 28. Ra8+ Kf7 29. Bb4 Nf6 30. Kf3 Rc2 31. Ra7+ Kg8 32. Ba3 b4 33. Bxb4 Rxb2 34. Bd6 Rb3+ 35. Kg2 Re3 36. Ra8+ Kh7 37. Ra7 Rxe2+ 38. Kh3 Rxe4 39. Bf8 Nh5 40. g4 Nf4+ 41. Kg3 Kg8 42. Bxg7 d3 |
| ECO A03 in 1970 play it! zuidema coenraad defeats white's jakobsen ole den in 58 moves | 1. f4 d5 2. Nf3 Nf6 3. g3 g6 4. Bg2 Bg7 5. d3 c5 6. O-O Nc6 7. Nc3 d4 8. Ne4 Nxe4 9. dxe4 O-O 10. Nh4 Bd7 11. Bd2 Qb6 12. Rb1 Rad8 13. Kh1 c4 14. Qe1 Bc8 15. Rf3 Rfe8 16. h3 Bf6 17. g4 c3 18. Bc1 Nb4 19. g5 Nxc2 20. Qd1 Nb4 21. bxc3 dxc3 22. Qa4 a5 23. e5 Bd7 24. Qb3 Be6 25. Qxc3 Rd1+ 26. Kh2 Qg1+ 27. Kg3 Rc8 28. Qa3 Qe1+ 29. Rf2 Rc3+ |
| ECO A01 in 1975 play it! zuidema coenraad defeats white's liljedahl lennar in 80 moves | 1. b3 d5 2. Bb2 c6 3. e3 Nf6 4. f4 g6 5. Nf3 Bg4 6. Be2 Bg7 7. O-O O-O 8. Qe1 Bxf3 9. Rxf3 e6 10. Rh3 Ne4 11. Bxg7 Kxg7 12. d3 Qf6 13. c3 Nd6 14. d4 Nd7 15. Bd3 c5 16. g4 Qe7 17. Nd2 Rac8 18. Nf3 Nf6 19. Qh4 Rh8 20. Qh6+ Kg8 21. Ne5 cxd4 22. cxd4 Nfe4 23. Rf1 Qf8 24. Qh4 Qd8 25. Qh6 Qf8 26. Qh4 h6 27. Bxe4 Nxe4 28. f5 gxf5 29. gxf5 Qg7+ 30. Qg4 Qxg4+ 31. Nxg4 h5 32. Ne5 Rh7 33. f6 Rh6 34. Rhf3 Kf8 35. Rf4 Ke8 36. Kh1 Rc3 37. R1f3 Rc1+ 38. Rf1 Rxf1+ 39. Rxf1 Rxf6 40. Rg1 Nf2+ |
| ECO A00 in 1970 play it! zuidema coenraad defeats white's jongsma alexande in 82 moves | 1. Nc3 Nf6 2. e4 e5 3. g3 Bc5 4. Bg2 d6 5. d3 Nc6 6. h3 Be6 7. Nge2 h6 8. Nd5 Bxd5 9. exd5 Ne7 10. Nc3 Nf5 11. Na4 Qd7 12. c3 O-O 13. b4 Bb6 14. O-O Rfe8 15. Kh2 Ne7 16. Rb1 Rad8 17. Nxb6 axb6 18. Qb3 Ra8 19. Bd2 Qa4 20. Rb2 Qxb3 21. axb3 Ra3 22. b5 Nexd5 23. c4 Ne7 24. Bxb7 Nf5 25. Bb4 Ra7 26. Bc6 Re7 27. Re1 Nd7 28. Be4 Nd4 29. Bc3 Nc5 30. b4 Nxe4 31. Rxe4 f5 32. Re3 Kf7 33. Kg2 Ra3 34. Be1 g5 35. Rd2 f4 36. gxf4 gxf4 37. Re4 Re6 38. h4 Rg6+ 39. Kh3 Rg1 40. Rd1 Nf3 41. Re2 Ra8 |
| ECO C28 in 1970 play it! zuidema coenraad defeats white's van der weide pi in 86 moves | 1. e4 e5 2. Nc3 Nf6 3. Bc4 Nc6 4. d3 Bc5 5. Be3 Bb6 6. Nge2 d6 7. Qd2 Be6 8. Bb3 d5 9. exd5 Nxd5 10. Nxd5 Bxd5 11. O-O O-O 12. Bxd5 Qxd5 13. Nc3 Qd7 14. Bxb6 axb6 15. Rae1 Rfe8 16. a3 Nd4 17. Re4 f5 18. Ree1 Rad8 19. f3 c5 20. Rf2 Qc6 21. Qe3 b5 22. Nb1 Ne6 23. Ref1 Nf4 24. Nc3 b4 25. axb4 cxb4 26. Ne2 Nd5 27. Qd2 Qb6 28. Ng3 Ne3 29. Re1 f4 30. Ne4 Qd4 31. Qc1 Rc8 32. Kh1 Rc6 33. Qb1 Ra8 34. c3 Qa7 35. d4 exd4 36. cxd4 Qxd4 37. Rd2 Qe5 38. Rc1 b3 39. Rc3 Rca6 40. Qe1 Nc2 41. Rdxc2 bxc2 42. Rxc2 Ra1 43. Rc1 Qxb2 |
| ECO C86 in 1966 play it! zuidema coenraad defeats white's villarroel geber in 68 moves | 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Qe2 b5 7. Bb3 d6 8. c3 Na5 9. Bc2 c5 10. d4 Qc7 11. h3 O-O 12. Re1 Re8 13. dxe5 dxe5 14. Nbd2 c4 15. Nf1 Nb7 16. a4 Be6 17. Ne3 Rad8 18. axb5 axb5 19. Ng5 Bc8 20. Nd5 Nxd5 21. exd5 h6 22. Qh5 Bc5 23. Bh7+ Kf8 24. Ne4 Qb6 25. b4 cxb3 26. Nxc5 Nxc5 27. Ba3 Rxd5 28. Bb4 g6 29. Qxh6+ Ke7 30. Qg7 Qf6 31. Ra7+ Ke6 32. Qxf6+ Kxf6 33. Rc7 Nd3 34. Re3 b2 |
| ECO C95 in 1973 play it! zuidema coenraad defeats white's enklaar bert in 102 moves | 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 d6 8. c3 O-O 9. h3 Nb8 10. d4 Nbd7 11. Nbd2 Bb7 12. Bc2 Re8 13. Nf1 Bf8 14. Ng3 g6 15. a4 c5 16. d5 c4 17. Bg5 h6 18. Be3 Nc5 19. Qd2 Kh7 20. Ra3 Rb8 21. Rea1 Bc8 22. axb5 axb5 23. Qc1 Re7 24. Ra7 Rxa7 25. Rxa7 Nfd7 26. Qa1 Qb6 27. Nd2 Rb7 28. Ra8 Qc7 29. Ne2 Nb6 30. Ra3 f5 31. f3 f4 32. Bf2 Nd3 33. b4 Nxf2 34. Kxf2 Be7 35. Ra6 Bd7 36. Nf1 Bd8 37. Ng1 Nc8 38. Ne2 Ra7 39. Ke1 Qb6 40. Rxa7 Nxa7 41. Qa5 Qxa5 42. bxa5 Bxa5 43. Nd2 h5 44. Kd1 Bb6 45. Bb1 Kh6 46. Ba2 Kg5 47. Ke1 Bc5 48. Kf1 Nc8 49. Ke1 Nb6 50. Kd1 Kh4 51. Kc2 Bxh3 |
| ECO C25 in 1973 play it! zuidema coenraad defeats white's van der weide pi in 54 moves | 1. e4 e5 2. Nc3 Nc6 3. f4 exf4 4. Nf3 g5 5. h4 g4 6. Ng5 h6 7. Nxf7 Kxf7 8. Bc4+ d5 9. Nxd5 Kg7 10. Nxf4 Nf6 11. d3 Bc5 12. Rf1 Ne5 13. Be6 g3 14. Qe2 Bf2+ 15. Rxf2 gxf2+ 16. Qxf2 Qe8 17. Bxc8 Qxc8 18. Bd2 Qg4 19. Bc3 Nfd7 20. Kd2 Raf8 21. Rf1 Kh7 22. d4 Ng6 23. g3 Nxf4 24. gxf4 Nf6 25. Kd3 Rhg8 26. d5 Qh3+ 27. Kd4 c5+ |
| ECO C84 in 1969 play it! zuidema coenraad defeats white's diez del corral in 78 moves | 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. d3 d6 7. c3 O-O 8. Nbd2 Re8 9. Re1 Bf8 10. Nf1 g6 11. Bg5 Bg7 12. Ne3 h6 13. Bh4 b5 14. Bb3 Qd7 15. Bxf6 Bxf6 16. d4 Bg7 17. Nd5 Qd8 18. dxe5 Nxe5 19. Nxe5 dxe5 20. Qf3 Ra7 21. Qe3 Rb7 22. Rad1 Qg5 23. Qxg5 hxg5 24. Ne7+ Rxe7 25. Rd8+ Bf8 26. Rxc8 Rd7 27. Re8 c6 28. Rxe5 Be7 29. Re3 Kg7 30. Rf3 Bf6 31. Rc5 Rbc7 32. e5 Bd8 33. g4 Rd2 34. c4 Be7 35. Rxc6 Rxc6 36. cxb5 Rc1+ 37. Kg2 f6 38. bxa6 Rc6 39. a7 Ra6 |
| ECO C46 in 1963 play it! zuidema coenraad defeats white's moe mogens in 112 moves | 1. e4 e5 2. Nf3 Nc6 3. Nc3 g6 4. d4 exd4 5. Nxd4 Bg7 6. Be3 Nf6 7. Nxc6 bxc6 8. e5 Ng8 9. Bd4 Qe7 10. f4 Nh6 11. Bd3 O-O 12. Qd2 c5 13. Nd5 Qd8 14. Bxc5 d6 15. Ba3 Re8 16. Bb5 Qh4+ 17. g3 Rxe5+ 18. Be2 Rxe2+ 19. Qxe2 Qd8 20. Ne7+ Kf8 21. Nxc8 Qxc8 22. O-O-O Nf5 23. Qe4 Rb8 24. g4 Nh4 25. Rhe1 Qxg4 26. Qe7+ Kg8 27. Qxc7 Rc8 28. Qxd6 Nf5 29. Qd7 Qxf4+ 30. Kb1 Qb8 31. Rd3 h5 32. Rb3 Qc7 33. Qxc7 Rxc7 34. Rb8+ Kh7 35. b3 Rd7 36. Ra8 Nh4 37. Bb2 Nf3 38. Rh1 g5 39. Bxg7 Kxg7 40. c4 f5 41. c5 f4 42. b4 Rb7 43. a3 Nd4 44. Rd8 Nb5 45. c6 Rc7 46. Rd7+ Kf6 47. Rxc7 Nxc7 48. Kc2 Ke5 49. Kd3 g4 50. Rc1 h4 51. Rc5+ Kd6 52. Rh5 h3 53. Rh4 g3 54. hxg3 fxg3 55. Rxh3 g2 56. Rg3 Ne6 |
| ECO C55 in 1963 play it! zuidema coenraad defeats white's crabbendam h in 86 moves | 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. d3 Be7 5. O-O d6 6. c3 O-O 7. Nbd2 Na5 8. Re1 Nxc4 9. Nxc4 Re8 10. d4 exd4 11. Nxd4 d5 12. exd5 Nxd5 13. Qf3 c6 14. Bf4 Bc5 15. Bd6 Rxe1+ 16. Rxe1 Bxd4 17. cxd4 Be6 18. Be5 Qg5 19. a3 Nf6 20. Bxf6 gxf6 21. Nd6 Kg7 22. Ne4 Qg6 23. Ng3 Rd8 24. Nh5+ Kh8 25. Nxf6 Rxd4 26. h3 Rd3 27. Qf4 Kg7 28. Re5 h6 29. Nh5+ Kf8 30. Ng3 Bd5 31. Re1 h5 32. Qb8+ Kg7 33. Qe5+ Kh6 34. Nf5+ Kh7 35. Ng3 h4 36. Ne4 Bxe4 37. Rxe4 Rxh3 38. Qd4 Qg5 39. f4 Qg6 40. Qe5 Rg3 41. Re2 h3 42. f5 Rxg2+ 43. Kf1 Qg4 |
| ECO C68 in 1961 play it! zuidema coenraad defeats white's larussen gudmund in 84 moves | 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Bxc6 dxc6 5. Nc3 Bc5 6. Nxe5 Qg5 7. d4 Qxg2 8. Qf3 Qxf3 9. Nxf3 Ba7 10. Rg1 g6 11. Bf4 h5 12. Be3 Bg4 13. Ne5 Rd8 14. f3 Be6 15. O-O-O Ne7 16. Ne2 Bc8 17. c4 c5 18. d5 b6 19. Bg5 Bb7 20. Nf4 Rg8 21. Rg2 Bb8 22. Rgd2 Rd6 23. Ned3 f6 24. e5 fxe5 25. Nxe5 c6 26. Re1 Nf5 27. Nxc6+ Kf7 28. Ne5+ Kg7 29. Ne6+ Kh7 30. Bf6 Re8 31. Rg2 Rexe6 32. dxe6 Rxe6 33. Bh8 Nd4 34. Re3 Bxf3 35. Rg3 Kxh8 36. Nxg6+ Rxg6 37. Re8+ Kh7 38. Re7+ Kh6 39. Rxg6+ Kxg6 40. h3 h4 41. Kb1 Bg2 42. Re8 Bg3 |
| ECO C77 in 1962 play it! zuidema coenraad defeats white's rugiadini andrea in 72 moves | 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. Qe2 b5 6. Bb3 Be7 7. a4 Rb8 8. axb5 axb5 9. Nc3 O-O 10. O-O b4 11. Nd5 d6 12. h3 Nxd5 13. Bxd5 Qe8 14. Qc4 Bd7 15. d3 Bd8 16. Qa2 Be6 17. Bxe6 fxe6 18. Be3 b3 19. cxb3 Nb4 20. Qb1 c5 21. Bd2 Nc6 22. Be3 Na5 23. Nd2 Nxb3 24. Nxb3 Rxb3 25. Ra3 Qb5 26. Rxb3 Qxb3 27. f4 Bf6 28. fxe5 Bxe5 29. Rxf8+ Kxf8 30. Qf1+ Kg8 31. Bc1 Qc2 32. Kh1 Qb1 33. Qe1 Bxb2 34. Bd2 Qxd3 35. Bf4 Bc3 36. Qh4 Qf1+ |
| ECO C25 in 1971 play it! zuidema coenraad defeats white's van der weide pi in 74 moves | 1. e4 e5 2. Nc3 Nc6 3. f4 exf4 4. Nf3 g5 5. h4 g4 6. Ng5 d6 7. d4 h6 8. Nxf7 Kxf7 9. Bxf4 Nf6 10. Qd2 Qe7 11. O-O-O Nxe4 12. Nxe4 Qxe4 13. Bc4+ Kg7 14. Rhf1 Qg6 15. Rde1 Bf5 16. d5 Ne7 17. Re6 Bxe6 18. dxe6 Kg8 19. h5 Qxh5 20. Be3 Bg7 21. Rf7 Rh7 22. Bd3 Bxb2+ 23. Kxb2 Rxf7 24. exf7+ Kxf7 25. Qb4 Nc6 26. Qc4+ Ke7 27. Bd2 Qc5 28. Qxg4 Qd4+ 29. Qxd4 Nxd4 30. Bxh6 Rg8 31. Bf1 Nf5 32. Bd2 Ke6 33. Kc3 Rg3+ 34. Kb2 Ne3 35. Bd3 Nxg2 36. Be4 d5 37. Bh7 Ne3 |
| ECO C86 in 1963 play it! zuidema coenraad defeats white's ree hans in 95 moves | 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Qe2 b5 7. Bb3 d6 8. c3 Na5 9. Bc2 c5 10. d4 Qc7 11. Rd1 O-O 12. Bg5 Re8 13. dxe5 dxe5 14. Nbd2 Nh5 15. Be3 Bb7 16. g3 Rad8 17. Nf1 Nc4 18. b3 Na3 19. Ne1 Nxc2 20. Qxc2 c4 21. b4 Nf6 22. f3 Nd7 23. Qf2 Bc6 24. Rd2 Ra8 25. a3 a5 26. Rda2 Ra6 27. Nc2 Rea8 28. Nd2 Bb7 29. Nb1 Nb6 30. Kg2 Na4 31. Ne1 Rd8 32. Rd2 Rf8 33. Raa2 axb4 34. axb4 f5 35. exf5 Rxf5 36. Qf1 Raf6 37. Rf2 Rf8 38. Qe2 R5f7 39. Rc2 e4 40. f4 Bf6 41. Kg1 Rd7 42. Rc1 Rd3 43. Nxd3 exd3 44. Qf1 Qc6 45. Qg2 Qd7 46. Qf1 Re8 47. Bd2 Bd8 48. Re1 |