I usually stay away from Bc4 in the Sicilians, just because ...e6 severely limits the bishop's effectiveness.

The point is that White intends to play a closed Sicilian (playing d3 instead of d4) and wants to get the bad bishop outside the pawnchain. The other option (to get the bad bishop outside the pawn chain) would be Bb5ck.

I don't like 6.d3. In the Sicilian, white has two choices for challenging the center: d4 or f4. Failing to play either of these will allow black to equalize, as has happened in this position (though black's bishop is misplaced on g4 - 7...O-O would have been preferable). Since white has played Nf3, blocking the f-pawn, 6.d3 loses a tempo as a subsequent d4 will be necessary. 6.d4 immediately would have been stronger.

It's hard to see that Black got much out of the bargain, having spent two moves to achieve it. Check out the previous diagram and compare with this. Black has exchanged his c6-Knight for White's one at d2; and White has moved his Queen to e2 in the meantime. That might not seem much, but White's rooks, now in communication with each other, can choose to deploy almost anywhere on the back rank.

I think it better to wait to move the queen until the bishop is on e3 and then move it to make a battery on the c1-h6 diagonal. You could first scare the bishop off with h3 to accompish this.

As Black can't really do anything with the pin except exchange bishop for knight - not unwelcome for White - I'd be inclined to play the DSB out (to e3, probably), or else biff the enemy bishop, just to see if he would exchange on f3.

Interesting. My first thought was White could have done better, but this is quite OK. Black probably should have taken on f3 at move 12, which inconveniences White somewhat, as she would have had to retake with the g-pawn.. Instead of the pawn advance by White, I was thinking more of 12.h3, which just about forces Black to exchange bishop for knight, unless he's prepared after 12...Bh5 13.g4 to sacrifice a piece.

From a positional viewpoint, 11...e5 is worth considering, as it prevents white's only available break in the center (12.d4 exd4 13.cxd4 Nd7 gives black the e-file, and the B on g7 becomes active). It creates a hole on d5, but white has no good way to exploit it. After 12.e5, rather than 12...dxe5, 12...Nd5 looks good for black.

Black is not without compensation for the pawn deficit, having (for the moment) the more active pieces. But it's hard to see how this helps him very much. White's position contains a lot of potential energy, and presents no lasting weaknesses to speak of.

can;t white on his move trap the black bishop? 17. f3 Bf5 18. g4 Bxd3 19. Rd1?

Yes, white can win a piece here as vladyslav points out. 15...Ng4? is a blunder.

After this exchange, White is left with a 'bad' bishop - so-called as there are a lot of White pawns on dark squares, so limiting its mobility. Black's on the other hand, is a 'good' bishop. Note, by the way, that 'bad' bishops can sometimes be more useful than 'good' bishops. As it happens, White's has the potential to become a very handy piece indeed...

Black has left his e-pawn backward, standing on a half-open file. This also leaves Black rather weakened on the dark squares. It is hard to know whether the ...f5 advance has gained him much. I would have been very tempted to restrain it by playing 21.f4, and consider developing the bishop via b2 or (possibly better) a3.

Maybe Black should have accepted it. If he was simplifying in the hope of a drawish endgame, then white's offer fell into his plans. The Queen and pawn ending would have been very difficult for White to win - as all such endings are if the stronger side has no passed pawn, and lacks the means to create one quickly. After 27.Rd1 Rxd1 28.Qxd1 Qc7 would probably hold things together.

Black's response to the Q check was a mistake. Better chances of defence were held in 28...Kg7 29.Rd7ch Kh8 30.Qd1 Qe5, though after 31.Rxa7 Qe1ch the rook ending will be hard to hold. Note that White could not have continued her attack by, say, 30.Qf7 on account of 30...Re1#! Though 28...Kh8? was a mistake it led to even worse: 28...Rg8?? Instead 28...Qb8 would have held out longer (29.Rd7?? Re1#).

Pretty much a help mate by Black, and pin motif is always nice to see. Good game Jo - you always seemed to have the wood on your opponent, though he did have his chances.