[Event "Hoogovens"]
[Site "Wijk aan Zee"]
[Date "1971.01.15"]
[Round "4"]
[White "Ivkov, Borislav"]
[Black "Olafsson, Fridrik"]
[Result "1/2-1/2"]

1. c4 e5 2. Nc3 Nf6 3. g3 Bb4 4. Bg2 O-O 5. e4 Bxc3 6. bxc3 c6 7. Ne2 d5 8. cxd5 cxd5 9. exd5 Nxd5 10. O-O Nc6 11. Rb1 Nb6 12. d4 Be6 13. Qd2 Bd5 14. dxe5 Nxe5 15. Bxd5 Nxd5 16. Kh1 Qa5 17. c4 Qxd2 18. Bxd2 Nxc4 19. Rxb7 Rfe8 20. Be3 1/2-1/2