With White’s last move a common question is posed to Black’s Sicilian setup: how to best react to White’s ambitions on the f-file? Is f5 really a threat? Can Black ignore it? Black has many options, for example, 15…Nb4!? (my favourite), or 15…Nd7, or even 15…Rf8.
Everything depends on Black’s answers to the above question. Black’s evaluation of the situation in this game is that f5 is not really an immediate threat, so he ignored it and continued his normal development…
After a life-time of trying to understand the nature of mistakes in chess, I have come to the conclusion that every one has the right to make mistakes! (It makes the game so much more interesting!) Black’s evaluation of the pro’s and con’s of White’s intended f5-thrust was overly optimistic and based on some insufficiently worked out tactics.
The game now becomes very sharp…
16…exf5 17.exf5 d5!?
This is the crux of Black’s evaluation from move 15. Black has a threat of …Bc5+ winning the Queen, and he had calculated that if 18.Kh1 Bb4!? 19.Qf2 Ng4 20.Qh4 Nce5 Black would have sufficient counterplay. (This can be debated)
HOWEVER, Black has allowed himself to make a typical mistake in sharp Sicilian positions: to over-estimate his own threats and under-estimate the threats of his opponent…
Ignoring Black’s threat!
If now 18… Bc5+ 19.Nxc5 Rxe2 a fascinating position occurs…
It might be tempting to play the seemingly crushing 20.Nxd5, but Black has the shocker 20…Nb4!! which allows him to save the game:
Black’s defence is based on the x-ray attack on g2
After the more or less forced 21.Nxc7 Rxg2+ 22. Kh1 bxc5 White must still find some moves
Black’s threat of a discovered check seems fatal…
23.Bxa6!! (only) 23… Nxa6 24. Nd5 Rxc2
After 25.Kg1 the game would be roughly balanced
INSTEAD, returning to the position in analysis after 18… Bc5+ 19.Nxc5 Rxe2 White can win with the sober 20.Bxe2!:
The Black kingside is shattered. After 20… bxc5 21. Nxd5 Qa5 22. fxg6 hxg6 (22… fxg6 23. Bc4! is no better) 23. Rf4! there is very little Black can do against the threatened Rh4 and mate on h8. Seeing these variations, Grandmaster Gonda decided to not give a check on c5:
The Rook attacks the White Queen all the same. And of course, White ignores it!
Don’t you just hate it when your opponent ignores your threats! Now Black can not avoid disaster. If 19… Rxe2 20. Nxc7 Nd4 21. Bxe2! Nxe2+ 22. Kh1 and White has a winning material advantage.
There is nothing better
Black resigns (1-0)
Moral of the story: most losses by Black in the Sicilian Defence are due to improperly evaluating White’s chances along the f-file!