[Event "IBM"]
[Site "Amsterdam"]
[Date "1961.??.??"]
[Round "6"]
[White "Van den Berg, Carel"]
[Black "Wolthuis, Willem"]
[Result "1/2-1/2"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 d6 5. c3 Bd7 6. d4 Nf6 7. O-O Nxe4 8. Re1 f5 9. dxe5 dxe5 10. Nbd2 Nxd2 11. Nxe5 Nxe5 12. Rxe5+ Be7 13. Bxd2 O-O 14. Bf4 Bd6 15. Bxd7 Qxd7 16. Rd5 Rad8 17. Qb3 Qe6 18. Bxd6 Rxd6 19. Rxd6 Qxb3 20. axb3 cxd6 21. Rd1 Rf6 22. Kf1 Re6 23. Rd4 Kf7 24. f3 Ke7 25. Rb4 b5 26. Rd4 Re5 27. Kf2 g6 28. b4 Kd7 29. Rd1 Kc6 30. Ra1 Kb6 31. Rd1 Kc6 32. g3 Re6 33. Rd3 Re5 34. b3 d5 35. Re3 Kd6 36. Rxe5 Kxe5 37. Ke3 g5 38. f4+ gxf4+ 39. gxf4+ Ke6 40. Kd4 Kd6 1/2-1/2