15. Kt-B3 Kt-QR3
This is in order to drive off the B. Black should have exchanged his own inactive QB, as the White B might become effective on the Diagonal QKt1-KR7, whilst Black’s QB has no future.
16. K-Kt2 Kt-B2 17. B-K2 B-Kt5
Black cannot yet castle, because of 18. B-Q3 Kt-KR3, 19. B-QB1).
18. Kt-R2 Kt-QR3 19. B-Q3 Kt-K2 20. R-QB1 Kt-B3 21. KtxB QKtxKt 22. B-Kt1
White’s last eight moves completed his development, and his Bishops lie in wait for the attack on the Black King. Meanwhile Black has effected nothing. On the contrary, he
Diag. 140
has exchanged his valuable KB, and also allowed his KKt to be driven off. His King’s side is bare, and castling would be fraught with danger. If Black castles now, White plays Kt-Kt5, and Black must weaken his position by P-R3 or P-Kt3, and White would advance his KtP or RP and force an exchange, opening a file for his Rook. In consequence Black decides to forfeit castling and to bring his KR to bear on the KB file. For this also Black must first play P-R3, and White obtains an open file by P-Kt4- Kt5. The sequel is shown here.
22. … P-R3 23. P-Kt4 Kt-K2 24. RxRch BxR 25. Kt-K1