[Event "IBM"]
[Site "Amsterdam"]
[Date "1962.08.17"]
[Round "4"]
[White "Donner, Jan Hein"]
[Black "Heidenfeld, Wolfgang"]
[Result "1/2-1/2"]

1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 dxc4 5. a4 e6 6. e3 Bb4 7. Bxc4 Qa5 8. Bd2 Nbd7 9. e4 e5 10. dxe5 Nxe5 11. Nxe5 Qxe5 12. Qb3 Bxc3 13. Bxc3 Qxe4+ 14. Kf1 O-O 15. Bb4 Bf5 16. f3 Qf4 17. Bxf8 Rxf8 18. Rd1 Ng4 19. Bxf7+ Kh8 20. g3 Qc7 21. fxg4 Be4 22. Rg1 Rxf7+ 23. Ke1 Bd5 24. Qd3 Qe5+ 25. Qe2 Qxe2+ 26. Kxe2 Bf3+ 27. Ke3 Bxd1 28. Rxd1 Re7+ 29. Kf4 Kg8 30. h4 Kf7 31. Rd8 c5 32. Rc8 b6 33. g5 Ke6 34. h5 Rd7 35. Re8+ Kf7 36. Rc8 Ke6 37. g4 g6 38. h6 Rd4+ 39. Kf3 Rd3+ 40. Kf4 Rd4+ 41. Kf3 1/2-1/2