Calculating Sacrifices

My opponent and I reached this unusual middlegame from the Classical Sicilian. Black's King is left all alone. And this usually signifies an attack. Black had just played Bb7 (see 1st diagram). So it is White to move.

Do you know what I was thinking?

1. Bxf7! was the sacrifice to open up the area around the Black King.

The question is: Do you think the sacrifice 1. Bxf7 works?

Calculate the lines after 1.... Kxf7.

Once you're ready, I'll go into the following thought processes that goes into my dysfunctional brain.

So please bear with me. :)

First of all, why 1. Bxf7? White has a positional advantage in that it has more active pieces and the pieces control a lot of squares on the board. True, I can play the slow way of squeezing my opponent to death with moves likes 1. a4, even h4 to break up the Black pawns and cramped Black further in.

Why sacrifice unnecessarily?

I believe that for a patzer player like myself, it is important to learn to see tactics and combinations where they occur. Rather than being afraid of playing bold moves, one should actively seek out good moves because that is the way a player can improve.

Anyway, back to the subject.

Does 1. Bxf7 work? Let's work it out.

What can Black reply with?

Looking at this, I calculated a few replies by Black. But I'll just explain one for the sake of brevity.

1..... Kxf7 is the natural response

2. Ng5+ (the natural followup, bringing another piece into the attack) Kg8 ( 2.... Kg7 or Kf8 runs into the horrible twin fork between King and Queen with Ne6+)
3. Ne6 (stifling the e7-pawn, effectively cutting off communication between Black Queen and King - see 2nd picture) Qd7 (forced)
4. Qd4 (Black is now forced to give up his Queen to prevent mate on g7)

Sweet.

I have actually calculated other lines as well including the replies
1 .... Rf8, 1.... Bxe4 but that discussion will take far too long for this post.

Instead, I'll leave you with a final puzzle after

1.... Rf8
2. Ng5 Bc8
3. Bd5 Nc6
4. Bxc6 (see 3rd diagram)

Now what happens if Black plays 4.... Qxc6?

Can you spot the mating pattern by White? Answers can be found by highlighting between the brackets. :)

[5. Rxe7+ leads to

..... 5. Kg8 leads to 6. Qc3 and mate on next move with 7. Qg7#
..... 5. Kh6 6. Rxh7#
..... 5. Kh8 6. Qd3+ Kg8 7. Qg7#
..... 5. Kf6 6. Rae1 and Black is going to be mated in the next few moves unable to stop mating threats with say Qd4+/Qf4+/Nh7+.]

Muddling Through Sacrifices

While working through "Perfect Your Chess", I decided to take a break and play a couple of online games on FICS.

I arrived at the following position. It's Black to play.

Black is under a bit of pressure. I find that going through the tactics book is starting to have some effect on my game.

I break down my line of thought as follows:

White has an extremely dangerous b-passed pawn and the only open file is the a-file and guarded by White's rook. If Black does not do something now, the White Knight on f1 becomes active and together with the b-passed pawn, Black will forced to be on the back foot for a long time.

Now have a look at White's pawn chain, the pawn chain while residing on dark squares, the Bishop lacks scope and dreadfully out of place and attacking the base of the pawn chain with the bishop takes too many moves.

However, there is a way to regain the initiative. Looking at this position, I played

1..... Bxb5! Sacrificing the bishop.

Why is it necessary to sacrifice the bishop here?

a. The bishop is not doing anything useful
b. White's pawn chain is very hard to break down.
c. Awkward placement of White's knight on f1 and possible back rank mate tricks.
d. 2 pawns for the sacrifice
e. The black c-pawn now become a dangerous passed pawn
f. The Black king is relatively safe
g. The Black Rook now has activity with an open b-file to work on

So after 2. cxb5 Rxb5 ... play becomes considerably sharper and the initiative has been passed to the Black side and it is White who must now tread carefully.

I won't bore you with the rest of the game but suffice it to say that White was forced to give back the piece and Black won eventually after a somewhat prolonged struggle. I was quite satisfied with this game.

Of course not every sacrifice works. When going for a sacrifice, especially an exchange sacrifice, both the short term and the long term strategy and aspects of the position must be taken into account and it is here where I spent a lot of time calculating lines and other variations. I have to say that it took me a long time before I decided to sac the bishop and I wasn't 100% certain it would work but it "looked" workable.

I am still trying to understand how exchange sacrifices work and how to fathom when such a strategy works and when it does not, especially in dynamic positions. It's definitely not easy.