15…Ne7So far Black's moves admit of no censure. But here the question arises, why Black failed to play the strong move of P - K B 3. If 16) Q - R 4, Black would break the attack by B - B 4.
16.Nd4Now White obtains at least the advantage of two Bishops. 16) ..., Kt - Kt 3; 17) Q - Kt 3 and the K B P threatens to advance, and if 16) ..., P - Kt 5?, White plays 17) Kt - Kt 3. Black is already somewhat in difficulty.
16…Bxd4Now the point Q B 4 becomes very weak, so that the Q B P is prevented from advancing and remains in want of support by the pieces.
21…Ra4And finally a blunder, which costs a Pawn. Schlechter was particularly indisposed at St. Petersburg.
44.Qb5White's play in this game appears most accurate and sound.
Emanuel Lasker, The International Chess Congress, St. Petersburg, 1909 (1910) · Public domain · source