[Event "IBM"] [Site "Amsterdam"] [Date "1970.??.??"] [Round "2"] [White "Jongsma, Alexander"] [Black "Spassky, Boris"] [Result "0-1"] [WhiteElo ""] [BlackElo ""] [ECO "B80"] 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e6 6. g3 Be7 7. Bg2 O-O 8. O-O a6 9. Be3 Qc7 10. Qe2 Nc6 11. Rad1 Bd7 12. h3 b5 13. a3 Rfc8 14. f4 Rab8 15. Nxc6 Bxc6 16. Bc1 a5 17. Rfe1 b4 18. axb4 axb4 19. Nd5 exd5 20. exd5 Bd7 0-1

[Event "IBM"] [Site "Amsterdam"] [Date "1970.??.??"] [Round "9"] [White "Gligoric, Svetozar"] [Black "Jongsma, Alexander"] [Result "1/2-1/2"] [WhiteElo ""] [BlackElo ""] [ECO "A50"] 1. d4 Nf6 2. c4 Nc6 3. d5 Ne5 4. e4 e6 5. Nf3 Bb4+ 6. Bd2 Bxd2+ 7. Nbxd2 d6 8. Nxe5 dxe5 9. Qa4+ c6 10. dxc6 O-O 11. c5 bxc6 12. Nb3 a5 13. Rd1 Qc7 14. f3 Bd7 15. Nd2 Qa7 16. Qa3 Bc8 17. Nc4 Nd7 18. Rc1 Ba6 19. Qxa5 Nxc5 20. Nb6 Bxf1 21. Qxc5 Bxg2 22. Nxa8 Qxc5 23. Rxc5 Bxh1 24. Nb6 Bxf3 25. Rxc6 Bxe4 26. Rc7 f5 27. a4 f4 28. a5 Bh1 29. a6 e4 30. Rc8 Rxc8 31. Nxc8 e3 32. Ke2 Kf8 33. a7 e5 34. b4 Bc6 35. Nb6 Ke7 36. a8=Q Bxa8 37. Nxa8 Kd6 38. Nb6 g5 39. Nc4+ Kd5 40. b5 Kc5 41. b6 Kc6 42. Nxe5+ Kxb6 43. Nf7 g4 44. Ne5 h5 1/2-1/2