[Event "Goteborg"] [Site "?"] [Round "0"] [White "Pilnik"] [Black "Geller"] [Result "0-1"] [ECO "B33"] [Opening "Sicilian: Open, 2...Nc6"] {The screened backward pawn} 1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 d6 6. Be2 e5 7. Nb3 Be7 8. O-O O-O 9. Be3 Be6 10. Bf3 a5 {sharp} (10... Na5 11. Nxa5 Qxa5 12. Qd2 Rfc8 { The half-open c-file fully compensates Black for his backward d-pawn} 13. Rfd1 Qb4 14. Rab1 h6 15. a3 Qc4 16. Rbc1 a6 17. Be2 Qc7 18. f3 Nd7 19. Bf1 b5 20. a4 b4 21. Nd5 Bxd5 22. Qxd5 Nc5 23. b3 Bg5 {Boleslavsky-Euwe, Zurich 1953}) 11. Nd5 (11. a4 {Black would not have much difficulty in the long run in arriving at the freeing advance ... Pd5}) 11... Bxd5 12. exd5 Nb8 13. c4 Na6 {The cards are on the table: White must advance his Queenside majority, Black his Kingisde majority. White's troubles lie in the fact that he will find it very difficult to get control of the c5 square, especially after Black's last move} 14. Bd2 {This is not in accordance with the needs of the position} (14. Nd2 { preapring Pb4 as soon as possible} 14... Nd7 15. Be2 f5 16. f3 Bf6 17. Rb1 Nac5 18. b3 {Pa3-Pb4}) 14... b6 15. Bc3 Nc5 16. Nxc5 bxc5 17. Qe1 (17. Qd3 g6 18. Be2 Nd7 19. f4 f5 {Black's pawn majority becomes more active than Whites}) 17... Nd7 18. Bd1 a4 $1 { This prevents White's bishop from getting into the thick of the fight via a4} 19. Bc2 f5 20. Rd1 (20. f4 e4 21. g4 {White's best chance}) 20... g6 21. Qe2 Bf6 22. f3 e4 $3 23. Bxf6 Qxf6 24. fxe4 f4 $1 {Black's pawn sacrifice has brought him a whole string of positional advantages 1) His 3-2 majority on the Kingside is now extremely active 2) He controls the vital e5 square, and cna plant a Knight there as a blockader 3) The hapless White Bishop is no match at all for the Black Knight} 25. Rf2 Ne5 26. Rdf1 Qh4 27. Bd1 Rf7 28. Qc2 g5 { Now the storm troops move into action} 29. Qc3 Raf8 30. h3 h5 31. Be2 g4 32. Rxf4 {One last attempt to save the situation} 32... Rxf4 33. Rxf4 Rxf4 34. g3 Nf3+ {This intermediate check ruins White's plans} 35. Kf2 (35. Bxf3 Qxg3+) 35... Qxh3 36. gxf4 g3+ 37. Kxf3 g2+ 38. Kf2 Qh2 $1 0-1