[Event "Amsterdam IBM"] [Site "Amsterdam NED"] [Date "1961.06.05"] [EventDate "1961.05.25"] [Round "10"] [Result "0-1"] [White "Willem Wolthuis"] [Black "H Crabbendam"] [ECO "A50"] [WhiteElo "?"] [BlackElo "?"] [PlyCount "110"] 1. d4 Nf6 2. c4 b6 3. Nc3 Bb7 4. Qc2 g6 5. e4 d6 6. f4 Bg7 7. Nf3 Nbd7 8. Be2 e5 9. fxe5 dxe5 10. dxe5 Ng4 11. e6 Nde5 12. exf7+ Nxf7 13. h3 Nge5 14. Be3 O-O 15. O-O c6 16. c5 b5 17. Rad1 Qe7 18. Rd2 Bc8 19. Rfd1 g5 20. Rf1 g4 21. Nxe5 Nxe5 22. Rxf8+ Bxf8 23. hxg4 Bxg4 24. Bxg4 Nxg4 25. Bd4 h5 26. Nd1 Rd8 27. b4 Bh6 28. Be3 Bxe3+ 29. Nxe3 Nxe3 30. Rxd8+ Qxd8 31. Qb3+ Nc4 32. Qg3+ Kh7 33. Qf3 Qe8 34. Qf5+ Qg6 35. Qd7+ Kh6 36. Qxa7 Qxe4 37. Qf7 Qe1+ 38. Kh2 Qh4+ 39. Kg1 Qe1+ 40. Kh2 Qe5+ 41. Kh3 Qe3+ 42. g3 Qg5 43. Qe6+ Qg6 44. Qe7 Qg4+ 45. Kg2 Qf5 46. Qe8 Qf6 47. Qe2 Ne5 48. Qd1 Ng6 49. a4 bxa4 50. Qxa4 h4 51. gxh4 Nxh4+ 52. Kg3 Kg5 53. Qc2 Qf4+ 54. Kh3 Qg4+ 55. Kh2 Nf3+ 0-1