St. Petersburg 1909, Game No. 14. A Ruy Lopez in which Lasker opens the Queen's file early and turns Black's weakness at Q B 4 into a decisive attack.
6.dxe5The Queen's file being opened by this exchange, the game takes altogether an open character.
10.Bh4If 10) .... P - K Kt 4; 11) B - Kt 3, Kt X P; 12) Kt X P and neither with 12) .... Kt X Kt; 13) B X Kt, nor with 12) .... Kt X B; 13) B X Kt, B X B; 14) B P X Kt would Black then have a satisfactory position.
14…b5Now Black's Q B 4 is very weak; and this actually causes the catastrophe that follows later on.
18…Rg8If here 18) .... Kt X Kt; 19) P X Kt, P - Q 4, then 20) P - Q 4, and after the exchange of the Pawns Black's King would be exposed.
21.Qe1Trying to avoid B - B 5. After 21) .... Kt X Kt; 22) Kt - Kt 2 White might well have played 22) P - Q R 4.
33.Qf2The Bishop at Kt 6 was in danger, therefore B - K 3 was indicated. But, in this case, White would obtain a decisive attack by 34) R (R sq) - K B sq followed by R - B 6.
Emanuel Lasker, The International Chess Congress, St. Petersburg, 1909 (1910) · Public domain · source