[Event "IBM"]
[Site "Amsterdam"]
[Date "1962.08.17"]
[Round "4"]
[White "Dunkelblum, Arthur"]
[Black "Rellstab, Ludwig Sr"]
[Result "1/2-1/2"]

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 c5 5. dxc5 Na6 6. Bd2 O-O 7. a3 Bxc3 8. Bxc3 Nxc5 9. Nf3 Re8 10. e3 b6 11. Be2 Bb7 12. O-O Rc8 13. Nd2 d5 14. Qd1 Nce4 15. Bxf6 Nxf6 16. cxd5 Bxd5 17. Ba6 Rc7 18. Rc1 1/2-1/2