[Event "Burnaby op"] [Site "Burnaby CAN"] [Date "1971.02.14"] [Round "4"] [White "Clark, Duane"] [Black "Thorvardson, Barry"] [Result "1-0"] [ECO "B85"] [EventDate "1971.02.13"] [PlyCount "57"] [EventType "swiss"] [EventRounds "5"] [EventCountry "CAN"] 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be3 e6 7. Be2 Be7 8. O-O Qc7 9. f4 O-O 10. g4 e5 11. Nf5 exf4 12. Rxf4 Be6 13. g5 Ne8 14. Rh4 Nc6 15. Bd3 g6 16. Qg4 Ne5 17. Qh3 h5 18. Rf1 Ng7 19. Qg3 Nxd3 20. Nxg7 Nxb2 21. Bd4 Qc4 22. e5 Bg4 23. Rf4 Bxg5 24. Nxh5 f5 25. Nf6+ Rxf6 26. exf6 Bxh4 27. Qxh4 Rf8 28. Rxf5 gxf5 29. Qg5+ 1-0