Find the move!

From a blitzgame yesterday. Richter-Rauzer Sicilian (5+0), white to move:

So, what’s next? A hint: You know you can’t afford to make a mistake in a sharp line if you follow one of Fritz‘ main lines for almost 10 moves and still manages to end up with a completely lost position.

I have displaced the answer: The moves that followed are placed some lines below, and if you don’t want to know before you’ve looked at the problem just click the picture right now to see the position in full view – then it will be a lot easier to analyze without letting your eyes ’slip downwards’…

…

…

…

…

…

…

…

…

…

…

…

…

…

…

…

…

Ok, the move is: 1.Nd5! My opponent played …Qc5+, the other non-losing move is of course just …exd5 without the check. Fritz prefer to let the Queen stay on the 7th rank, and it probably does lead to better chances of a draw – black gets to keep the bishop if he doesn’t check and he doesn’t lose that second pawn. In short, the check was not the best defence, and in this position the second best move just isn’t good enough. In the game, the line that followed (after the check) was: 2.Kh1…exd5, 3.Bxd5+…Be6, 4.Bxe6…Nxe6, 5.Qf7+…Kh8, 6.Qxe7…Qe5, 7.Qxb7…Rg8, 8.Qd5…Qxd5, 9.exd5. Now black is simply two pawns down, the queens are off the board (so no perpetual), and he furthermore has two isolated pawns far away from the king – a king with very low mobility due to the rook on the 7th rank. The position is lost. Fritz also gives a line without 7.Qe5, where the black queen go to the c4-square instead. It’s better, but black is still in deep trouble. All that because of that first move that didn’t even look all that strong (and now you ask: Did I really see that far? Well, no it was blitz. I had a good idea what was going to happen until Qxe7 but not after that. Incidentally I more or less took it for granted that he would check on c4 – though I did figure I wouldn’t loose material if he didn’t and it ‘looked interesting’ either way – and this is bad: Expecting your opponent to play the inferior move is always a very bad strategy).

If no check on c5 it would probably have looked something like this: 1…exd5, 2.Bxd5…Be6, 3.Bxe6+…Nxe6, 4.Qf7+…Kh8, 5.Qxe6…Bf6. Black is better off than he was in the game, as white’s e-pawn and a-pawn are both hanging and he gets to keep the bishop (and the queen), but of course black still has to fight hard to obtain a draw.