[Event "IBM"]
[Site "Amsterdam"]
[Date "1973.??.??"]
[Round "6"]
[White "Donner, Jan Hein"]
[Black "Petrosian, Tigran V"]
[Result "1/2-1/2"]

1. d4 e6 2. c4 Bb4+ 3. Nc3 Nf6 4. e3 c5 5. Bd3 b6 6. Ne2 cxd4 7. exd4 O-O 8. d5 Re8 9. O-O Na6 10. a3 Be7 11. Nd4 Bb7 12. Bf4 Bf8 13. Ndb5 exd5 14. cxd5 d6 15. Rc1 Nc5 16. Bc4 a6 17. Nd4 b5 18. Ba2 Qd7 19. Qf3 Qg4 20. Qxg4 Nxg4 21. Rfd1 Ne5 1/2-1/2