[Event "URS-ch39 Semifinal"]
[Site "Daugavpils"]
[Date "1971.06.??"]
[Round "?"]
[White "Ruderfer, Mark B"]
[Black "Karpov, Anatoly"]
[Result "0-1"]

1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. g3 dxc4 5. Bg2 b5 6. a4 c6 7. O-O Bb7 8. Nc3 a6 9. e4 Nbd7
10. Qe2 Be7 11. e5 Nd5 12. Ne4 h6 13. h4 Qc7 14. Bd2 c5 15. axb5 axb5 16. dxc5 Rxa1 17.
Rxa1 Nxc5 18. Nxc5 Bxc5 19. b3 O-O 20. bxc4 bxc4 21. Qe4 Ne3 22. Qf4 Nxg2 23. Kxg2 Qc6 24.
Rd1 Rd8 0-1