[Event "Olympiad-23"]
[Site "Buenos Aires"]
[Date "1978.11.08"]
[Round "13"]
[White "Aldrete, Jorge"]
[Black "De Greif, Boris"]
[Result "1/2-1/2"]
[WhiteElo "2310"]
[BlackElo "2335"]

1. d4 Nf6 2. Nf3 g6 3. Bg5 Bg7 4. Nbd2 d5 5. e3 O-O 6. Bd3 c5 7. c3 Nc6 8. O-O Qb6 9. Rb1 Re8 10. b4 cxb4 11. cxb4 Bg4 12. Qb3 Bxf3 13. Nxf3 e6 14. Rfc1 Rec8 15. a3 Ne8 16. Bf4 Bf8 17. Qa2 a6 18. Rc2 f6 19. h4 Na7 20. Rbc1 Rxc2 21. Rxc2 Rc8 22. Rxc8 Nxc8 23. Qc2 Ne7 24. h5 Kf7 25. hxg6+ hxg6 26. g4 Qc6 27. g5 Qxc2 28. Bxc2 Bg7 29. gxf6 Bxf6 30. Ng5+ Bxg5 31. Bxg5 Nc6 32. Bf4 Nf6 33. Kf1 b5 34. Bc7 Ne4 35. Ke2 Nc3+ 36. Kd3 Na4 37. Kd2 g5 38. Kc1 Kf6 39. Bd1 Kg6 40. Kc2 Kf6 41. Bh5 Ke7 42. Be2 1/2-1/2