Lesson
White to move. Main line: 1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Nf3 c5 5. Bg5 cxd4 6. Qxd4 Nc6 7. Qh4 Be7 8. O-O-O Qa5 9. e3 Bd7 10. Kb1 h6 11. cxd5 exd5 12. Nd4 O-O 13. Bxf6 Bxf6 14. Qh5 Nxd4 15. exd4 Be6 16. f4 Rac8 17. f5 Rxc3 18. fxe6 Ra3 19. exf7+ Rxf7 20. bxa3 Qb6+ 21. Bb5 Qxb5+ 22. Ka1 Rc7 23. Rd2 Rc4 24. Rhd1 Rc3 25. Qf5 Qc4 26. Kb2 Rxa3 27. Qe6+ Kh7 28. Kxa3 Qc3+ 29. Ka4 b5+ 30. Kxb5 Qc4+ 31. Ka5 Bd8+ 32. Qb6 Bxb6#
After White’s ambitious f4–f5, Lasker does not retreat. The exchange sacrifice 17...Rxc3! removes the c3-knight and gives the rook access to a3, where it attacks the king and forces White’s b-pawn to recapture later.
The sequence ...Ra3, ...Qb6+ and ...Qxb5+ strips away the king’s shelter. Although Pillsbury wins the rook on a3, Black’s queen and remaining rook keep checking while White’s pieces cannot organize a defense.
The final chase from a3 to a5 ends with 31...Bd8+ 32.Qb6 Bxb6#. For study, pause before 17...Rxc3 and compare material with forcing moves: Lasker’s compensation is not vague—every check narrows the king’s route until the bishop closes the net.