[Event "IBM"]
[Site "Amsterdam"]
[Date "1970.07.17"]
[Round "4"]
[White "Ciric, Dragoljub M"]
[Black "Donner, Jan Hein"]
[Result "1/2-1/2"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 d6 8. c3 O-O 9. h3 h6 10. d4 Re8 11. Nbd2 Bf8 12. Nf1 Bd7 13. Ng3 Na5 14. Bc2 c5 15. b3 Nc6 16. d5 Ne7 17. Nh2 Ng6 18. Nf5 Nf4 19. c4 g6 20. Ng3 Bg7 21. Rb1 h5 22. Qf3 h4 23. Ne2 g5 24. Nc3 Rb8 25. Bd2 bxc4 26. bxc4 Rb4 27. Bb3 Qc7 28. Nd1 a5 29. Bxb4 cxb4 30. Ne3 a4 31. Bc2 Rb8 32. Nhg4 Nxg4 33. hxg4 Qc5 34. g3 hxg3 35. fxg3 Qd4 36. Red1 Bxg4 37. Rxd4 Bxf3 38. Rd2 Nh3+ 39. Kh2 g4 40. Nf5 Ng5 41. Nxd6 Bf8 42. c5 Bxd6 43. cxd6 Nxe4 44. Bxe4 Bxe4 45. Rc1 Rd8 46. Rc4 f5 47. Rxb4 a3 48. Ra4 Rxd6 49. Rxa3 Kf7 1/2-1/2