[Event "St.Petersburg"] [Site "St.Petersburg-1"] [Round "0"] [White "Nimzowitsch"] [Black "Tarrasch"] [Result "0-1"] [FEN "3r1rk1/p3qp1p/2bb2p1/2pp4/4n3/1P2PN2/PBQN1PPP/2R2RK1 b - - 0 17"] {Double Bishop sacrifice} 17... Nxd2 {Although piece exchanges are usually considered to be undesirable to the owner of hanging pawns, the exchange is very stron here due to tactical possibilities} 18. Nxd2 (18. Qxd2 d4 19. -- Bxf3) 18... d4 $1 19. exd4 Bxh2+ 20. Kxh2 Qh4+ 21. Kg1 Bxg2 22. f3 (22. Kxg2 Qg4+ 23. Kh2 Rd5 $19 {thematic Queen and Rook}) 22... Rfe8 $1 { This quiet move cuts off the White King's flight via the e-file} 23. Ne4 (23. -- Re2) (23. Qd3 Qg3 24. Ne4 Rxe4 {removing the guard} 25. fxe4 Bf3#) 23... Qh1+ 24. Kf2 Bxf1 25. d5 { A dangerous counteraction along the long dark-squared diagonal} (25. Rxf1 Qh2+ $19 {skewer}) 25... f5 $1 26. Qc3 Qg2+ 27. Ke3 Rxe4+ { Leading to a pretty and forced finish} 28. fxe4 f4+ 29. Kxf4 Rf8+ 30. Ke5 Qh2+ 31. Ke6 Re8+ 32. Kd7 Bb5# 0-1