[Event "Carlsbad"] [Site "?"] [Round "0"] [White "Salwe"] [Black "Schlechter"] [Result "1-0"] [ECO "C55"] [Opening "Two Knights: 4.d3"] {The value of the open files associated with doubled pawns} 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. d3 Bc5 5. Nc3 d6 6. Be3 Bxe3 7. fxe3 Na5 8. Bb3 Nxb3 9. axb3 { White has two doubled pawns, and therefore two open files. No less anauthority than Steinitz was of the opinoun that this position was in Black's favour, maintaining that the doubles pawns must be considered a serious handicap to White} 9... Ng4 10. Qd2 f5 (10... f6 {Steinitiz} 11. -- Nh6 12. -- Nf7 { In such a position, however, Black must be prepared for a long defensive game, and in due course Tarrasch pronounced the text to be a bettermove}) 11. exf5 Bxf5 12. O-O O-O 13. h3 Nh6 {Here the Knight is badly placed} (13... Nf6 14. Nxe5 $1 Bxh3 $1 15. Ng6 $1 hxg6 16. gxh3 { Black is the one left with weak isolated doubled pawns}) 14. e4 Bd7 15. d4 { Thanks to the open a-file, this advance is particularly powerful} 15... Nf7 ( 15... exd4 16. Qxd4 b6 17. e5 dxe5 18. Qd5+ Kh8 19. Nxe5 Bf5 20. Qxd8 Raxd8 21. Rf2 {threat Rxa7 and Raf1}) 16. dxe5 dxe5 17. Rfd1 Nd6 (17... Bc6 18. Qxd8 { either a-pawn or e-pawn falls}) 18. Nxe5 Be6 19. Nf3 Rxf3 { An attempt to salvage a strategically lost game by tactical means} 20. gxf3 Qh4 21. Ra5 $1 { The a-file is still very much in evidence. The entry of the Rook is decisive} 21... Rf8 22. Qf2 Qxh3 23. Rd3 b5 (23... -- 24. Rg5 -- 25. Qg2) 24. Qh2 $1 (24. Nxb5 Rf6) 24... Qxh2+ 25. Kxh2 g5 26. e5 Nf7 27. Rxb5 g4 28. fxg4 Ng5 29. Rc5 Rf2+ 30. Kg3 Rf7 31. Re3 Rf1 32. Ne4 Rg1+ 33. Kf2 Rxg4 34. Nxg5 Rxg5 35. Rg3 1-0