[Event "IBM"]
[Site "Amsterdam"]
[Date "1961.??.??"]
[Round "9"]
[White "De Rooi, Paul"]
[Black "Bernstein, Ossip Samuel"]
[Result "1-0"]

1. c4 Nf6 2. Nc3 g6 3. d4 Bg7 4. e4 d6 5. Nf3 Bg4 6. Be3 O-O 7. h3 Bxf3 8. Qxf3 Nbd7 9. Rd1 c6 10. Be2 a6 11. O-O b5 12. e5 dxe5 13. Qxc6 b4 14. dxe5 Nxe5 15. Qa4 Qb8 16. Nd5 Nxd5 17. Rxd5 e6 18. Rd2 Rc8 19. b3 a5 20. f4 Nc6 21. Bf3 Ra6 22. Qb5 Qa8 23. Rfd1 Bf8 24. Rd7 a4 25. Qg5 axb3 26. Qf6 1-0