[Event "IBM"]
[Site "Amsterdam"]
[Date "1968.??.??"]
[Round "8"]
[White "Zuidema, Coen"]
[Black "Ree, Hans"]
[Result "1/2-1/2"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. Nc3 Bg7 6. Be3 Nf6 7. Bc4 Qa5 8. O-O O-O 9. Bb3 d6 10. h3 Bd7 11. f4 Nxd4 12. Bxd4 Bc6 13. Qd3 Rad8 14. Rad1 Nd7 15. Bxg7 Kxg7 16. Qd4+ Kg8 17. Nd5 Bxd5 18. Bxd5 Qc5 19. b4 Qxd4+ 20. Rxd4 Rc8 21. Bxb7 Rxc2 22. a4 Rb8 23. Bd5 Nf6 24. Bc4 Kg7 25. Ba6 Rb2 26. b5 Ra2 27. Rc1 Nh5 28. Rc7 Nxf4 29. Rb4 Kf6 30. Rxa7 Nd3 31. Rc4 Nc5 32. e5+ Kxe5 33. Rxe7+ Kd5 34. Rg4 f5 35. Rg3 Rh8 36. Bb7+ Nxb7 37. Rxb7 Rxa4 38. Rb3 Ra2 39. b6 Re8 40. Rxh7 Kc4 41. Rg3 Re1+ 42. Kh2 f4 43. Rc7+ Kd4 44. Rb3 Ree2 45. Rb4+ Kd3 46. Rb3+ Kd4 47. Rb4+ Kd3 48. Rb3+ 1/2-1/2