[Event "IBM"]
[Site "Amsterdam"]
[Date "1965.??.??"]
[Round "1"]
[White "Zuidema, Coen"]
[Black "Trifunovic, Petar"]
[Result "1/2-1/2"]

1. e4 Nf6 2. e5 Nd5 3. d4 d6 4. Nf3 Bg4 5. Be2 e6 6. O-O Be7 7. h3 Bh5 8. c4 Nb6 9. Nc3 O-O 10. exd6 cxd6 11. Be3 N6d7 12. b3 Nf6 13. Nd2 Bxe2 14. Qxe2 Nbd7 15. Rfd1 Qa5 16. Rac1 Rfc8 17. Nf3 d5 18. c5 b6 19. Bd2 Qa3 20. Be1 Nb8 21. b4 bxc5 22. dxc5 a5 23. Nb1 Qa4 24. a3 Na6 25. Rd4 Nc7 26. Ne5 Nb5 27. Rdd1 1/2-1/2