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

1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 a6 5. Bd3 g6 6. O-O Bg7 7. Be3 Ne7 8. f4 Nbc6 9. Nxc6 bxc6 10. Nd2 O-O 11. c3 d6 12. Qc2 Qc7 13. Rad1 c5 14. b4 cxb4 15. cxb4 Nc6 16. a3 Bb7 17. Nb3 Rfc8 18. Qf2 Qe7 19. Bb1 Rd8 20. Rd2 Rac8 21. Rfd1 Nb8 22. Bd4 Bc6 23. Bxg7 Kxg7 24. Qd4+ Kg8 25. Na5 Ba4 26. Rf1 1/2-1/2