[Event "Hoogovens 27th"]
[Site "Beverwijk"]
[Date "1965.01.09"]
[Round "4"]
[White "Portisch, Lajos"]
[Black "Bobotsov, Milko Georgiev"]
[Result "1/2-1/2"]

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. Nf3 d5 6. Bd3 b6 7. O-O Bb7 8. a3 Be7 9. b4 c5 10. bxc5 dxc4 11. Bxc4 bxc5 12. Rb1 Qc8 13. d5 exd5 14. Nxd5 Bxd5 15. Bxd5 Nxd5 16. Qxd5 Nc6 17. Bd2 Rd8 18. Qc4 Qe6 19. Qxe6 fxe6 20. Rfc1 Rab8 21. Bc3 Rxb1 22. Rxb1 Rd3 23. Rc1 c4 24. Ne1 Rd7 25. Nc2 Rd3 1/2-1/2