Game 16 in the book: Alekhine's win over O. Duras at the Masters' Quadrangular Tournament at St. Petersburg, 1913. A Ruy Lopez annotated by Alekhine, who plays White.
5…b5This move, in conjunction with the next one, affords Black the simplest method of equalizing the game.
7.a4The opening of the Q R file is of great moment in this variation. Black cannot prevent it, for if: 7. ....P—Kt 5; 8. B x P ch, K x B; 9. Q—B 4 ch, P—Q 4; 10. Q x B, Q—Q 3; 11. Q x Kt!
9.d3After 9. Kt—B 3, Black could simply Castle, for after 10. Kt x Kt P, P—Q 4! and he obtains an attack fully equivalent to the Pawn sacrificed. After the text-move White can eventually play P—B 3 and bring his Knight to K 3 or K Kt 3 via Q 2 and K B 1.
10…Bg4Here Black could have obtained an even game by forcing the exchange of White's only well posted piece, the K B, by 10. ....B—K 3. It is clear that White would not have reaped any advantage by exchanging at K 6 and Q B 4, as Black would have had command of the centre, thanks to his Pawn position and the two open files.
11…Bh5Consequent but not best. 11. ....B—K 3 was even now preferable and would have brought about variations similar to those resulting from the immediate development of the B at K 3.
13…Nd4This offer to exchange is premature, and, as will be seen, gives White a marked positional advantage. Relatively better would have been 13. ....Q—K 2 followed by Kt—Q 1—K 3, although in either case Black has the inferior game.
14…Bxf3Forced, for otherwise the Black Bishop would have been in jeopardy, e.g.: 14. ....B x B; 15. P—Kt 4, B—Kt 3; 16. Kt x B, P x Kt; 17. P—K B 4, etc., or 14. ....P x B; 15. P—Kt 4, B—Kt 3; 16. Kt—R 4, followed by P—K B 4, with advantage to White in either variation.
16.e5The beginning of a strong attack against Black's K B 2, weakened as it is by the premature exchange of Black's K B. Furthermore it is interesting to observe how important it is for White's attack to have the open Q R file.
16…Qe7Besides this move and the sequel it implies, Black had a further choice of two lines of play: I.—16. ....P x P; 17. Q x P, Q—Q 3; 18. Q x Q, P x Q; 19. K R—K 1 with advantage to White; or II.—16. ....K R—K 1; 17. P—K 6!, P x P; 18. B x P ch, K—B 1 (if K—R 1; 19. Kt—Kt 5); 19. P—Q Kt 4!, B x P (if B—Kt 3; 20. K R—K 1, etc.); 20. Kt x P, R—Kt 3!; 21. Q—B 3!, B—B 6; 22. Kt—B 6, R x Kt; 23. Q x R, B x R; 24. R x B, and White has the better game.
18…dxe5Forced, as P—K 6 was threatened.
20.Qg5Forcing a further exchange which brings the Knight into decisive action.
20…Rxe5It is clear that 20. ....P—R 3 would have achieved nothing after 21. Q—B 5.
21.Nxe5Already threatening mate after Kt x P.
21…Qb6Relatively best. 21. ....Kt—Q 2 would not be sufficient, e.g.: 21. ....Kt—Q 2; 22. Kt x P!, R x Kt; 23. R—R 8 ch, Kt—B 1; 24. Q—B 5!, Q—K 2; 25. B x R ch, Q x B; 26. Q x B and wins. The move in the text removes the immediate threat, for now 22. Q—B 5, would be insufficient as a preliminary to the Kt sacrifice, as Black could prepare a fresh defensive position by 22. ....P—Kt 3, followed by K—Kt 2, etc.
22.g4But this somewhat hidden preparation of the Kt sacrifice wins at once, as Black is compelled to make a reply which will render his position still more precarious.
22…Bd6If 22. ....P—Kt 3, then 23. Q—R 6 threatening either Kt x B P or R—R 8; and if 22. ....B—K 2; 23. Kt—Q 7!, Kt x Kt; 24. Q x B, Q—Q 3; 25. Q x Q, P x Q; 26. R—R 5, R—Kt 1; 27. R—R 7, R—Q 1; 28. R—Kt 7 and wins.
24.Qf5The point of the manoeuvre started with 22. P—Kt 4! Against the double threat of 25. B x R ch, followed by 26. P—Kt 5, or else 25. Q—K 6 Black has no defence.
24…g6If 24. ....Q—B 3; 25. P—Kt 5, Q—Q 2; 26. B x R ch, K x B (if Q x B; 27. P x Kt) 27. Q—B 3; and White wins.
Alexander Alekhine, My Best Games of Chess 1908–1923 (1927) · Public domain · source