[Event "USA-ch"]
[Site "Mentor"]
[Date "1977.09.28"]
[Round "4"]
[White "Grefe, John Alan"]
[Black "Shamkovich, Leonid Alexandrovic"]
[Result "1/2-1/2"]
[WhiteElo "2425"]
[BlackElo "2485"]

1. c4 Nf6 2. Nc3 c6 3. d4 d5 4. e3 g6 5. Nf3 Bg7 6. Bd3 O-O 7. O-O dxc4 8. Bxc4 Bg4 9. h3 Bxf3 10. Qxf3 Nbd7 11. Qe2 e5 12. d5 cxd5 13. Nxd5 e4 14. Nxf6+ Bxf6 15. Bd2 Qe7 16. a3 Nc5 17. Bb4 a5 18. Bxc5 Qxc5 19. Rac1 Qe5 20. a4 Rfd8 21. b3 1/2-1/2