[Event "IBM"]
[Site "Amsterdam"]
[Date "1962.08.25"]
[Round "9"]
[White "Heidenfeld, Wolfgang"]
[Black "Dunkelblum, Arthur"]
[Result "1/2-1/2"]

1. e4 c6 2. d4 d5 3. e5 Bf5 4. Ne2 e6 5. Ng3 Bg6 6. h4 h6 7. h5 Bh7 8. c3 c5 9. Bd3 Bxd3 10. Qxd3 cxd4 11. cxd4 Qa5+ 12. Nc3 Qa6 13. Nb5 Qb6 14. O-O a6 15. Nc3 Nc6 16. Be3 Nge7 17. f4 g6 18. hxg6 fxg6 19. Na4 Qb5 20. Qxb5 axb5 21. Nc3 b4 22. Nb5 Kd7 1/2-1/2