9. B-K3 Castles 10. Q-Q2 B-K3 11. B-Kt3
The first mistake. B-QKt5 should be played to retard P-Q4.
11. … BxB 12. PxB P-Q4
Diag. 132
13. PxP
The second mistake. Unimportant as it seems, it leads to the loss of the game. White did not defend the pawn by Q-B2, because it would have proved 10. Q-Q2 to have been a lost move. But giving up the centre is a far greater evil. Black now commands his Q5 and KB5, and this enables him to start an attack to which there is no defence. The game shows conclusively how important it is to maintain the centre.
13. … KtxP 14. Castles KR P-B4 15. P-QKt4 P-QKt3 16. Q-K2
to prevent P-K5, which would now be countered by PxP and Q-B4. However, as P-K5 cannot be prevented permanently, and the Q must move in any case, Q-B2 would have been the better move, as there the Queen cannot be molested by a Rook.
16. … Q-Q3 17. P-Kt5 QKt-K2 18. B-Q2 Kt-Kt3 19. R-R4 QR-K1!