The Bishop Sacrifice on h7/h2
The Bishop sacrifice on h7/h2 is one of the most important patterns to know in the
attack on the castled king. In describing the sacrifice, for simplicity's sake, we will consider that White is on the attack. This is particularly appropriate because the bishop sacrifice often arises in positions where White has a pawn on e5 (such as in some variations of the French Defense and other semi-open Defenses) which has driven away the defensive knight which might have been on f6. The earliest known example of the Bishop Sacrifice on h7/h2 is shown in Gioacchino Greco's handbook of 1619, where he gives the moves 1 e4 Nf6 2 e5 Nd5 3 d4 e6 4 Nf3 Be7 5 Bd3 O-O 6 h4 Nc6 and then 7 Bxh7+! Kxh7 8 Ng5+ with a winning attack. With deference to these groundbreaking notes, the sacrifice came to be known as Greco's Sacrifice. This not being the most typical setup, however, we will come back to this position later in the course.
The basic scenario is as follows: Black is castled on the kingside, and White has a bishop on d3, a knight on f3, and the queen is on d1. A good example is this variation from the game deFirmian – Shaked, 4th match game, 1998 U.S. Championship semi-finals. After the moves 1 e4 e6 2 d4 d5 3 Nc3 Bb4 4 e5 c5 5 a3 Bxc3+ 6 bxc3 Ne7 7 Nf3 Bd7 8 Bd3 Ba4 9 O-O Qc7 10 Re1, White is very well set up for Greco's sacrifice if Black castles kingside. These were my live comments, broadcast at http://www.uschess.org, to the position after 10 Re1:
Making a home on f1 for the bishop if it needs it. Meanwhile, White prevents the move ... f7-f6 for some time to come. Black will not play 10 ... O-O? because of 11 Bxh7+ Kxh7 12 Ng5+. And if Black plays 10 ... Nbc6 then 11 dxc5 seems good. Therefore, the likely moves are 10 ... Nd7 or 10 ... c4. Shaked is taking a lot of time here. He is probably considering (1) how Black gets winning chances after 10 ... c4, and (2) whether he should play 10 ... h6 and then castle kingside.
After 10 Re1, Shaked actually played 10 … h6. Following are my live comments to that move:
Shaked clearly wants to play the position without having to commit with ... c5-c4. 10 ... h6 is a preparation for kingside castling (not 10 ... O-O? 11 Bxh7+). A good waiting move here is 11 Rb1.
Ok, so the question is, what really happens on 10 … O-O 11 Bxh7+ - in the above notes, I just assumed that Greco's sacrifice would be very strong. Now let's put that assumption to the test. The variation runs 10 … O-O 11 Bxh7+ Kxh7 (on 11 … Kh8, Black just has a very bad game after 12 Bd3) 12 Ng5+ and then, the only choices are (a) 12 … Kg8, and (b) 12 … Kg6. Where White still has a dark-squared bishop, … Kh7-h6 will never be right (here 12 … Kh6 runs into 13 Nxe6+) and the move … Kh7-h8 is impossible because it will allow Qd1-h5 with check.
[full examination of the ramifications of deFirmian – Shaked]