TL Chess Match 4 - Page 62

Allowing black to castle significantly changes the tactics involved.

1) After Qa4, the c-pawn is no longer pinned. Black can play c5, defending his bishop, removing his pawn from attack, and undermining our pawn center. We can perhaps still win a pawn here after dxc5, but the position does not seem as favorable as playing Bxc6+ first.

9. O-O O-O 10. Bxc6 bxc6 11. Qa4 c5




2) Because we won't be capturing the c-pawn with check, black now doesn't have to exchange queens. He can play for example:

9. O-O O-O 10. Bxc6 bxc6 11. Qa4 Rb8 12. Qxc6 Rb6 13. Qc2 Bf5




3) Part of the strength of the Bxd2 line above is that we can threaten to occupy the a3- f8 diagonal, preventing black from castling. Black's c-pawn is hanging and he can't meet both threats at the same time:




Perhaps there are alternate moves for either side that are better. In either case, the position is less clear and less forcing, and seems to offer black better chances imo.

Assuming that we want to go ahead with our plan of doubling Black's c-pawns and trying to focus on that weakness, this is a move we'll have to play at some point. I spent a long time looking at alternatives, but they all seemed to boil down to the same basic ideas of Bxc6 (to double Black's pawns) and Qa4 (to pressure Black and to prevent ...Ba6). Voting for 9. Bxc6 over 9. 0-0 because it looks like in this line we can make it hard for Black to castle.

The one place I disagree with jdseemoreglass's line is after 9. BxN+ PxB 10. Qa4 BxN, jd wants to play 11. NxN, to exchange off Black's strong Knight at e4. I'd rather play 11. BxN, even at the cost of leaving Black's Knight where it is, because if we simplify down to an endgame where the only minor pieces are opposite-colored Bishops, I'm afraid that we won't be able to get more than a draw, as Boozerr said.