I missed a tactical opportunity in a recent online training game against a pupil.
I had black in this position.
I played 21.. Rad8 without thinking too much, when I should have preferred 21.. Bh3!. The point is that the immediate Be5 would be met with g3, so Black wants to deflect the g-pawn first: 22. gxh3 Be5 leads to mate. White can defend with 22. Nd3 Qg4 23. Ne1 Rad8, but his position would be hopelessly passive and disorganised. One threat is Be5 followed by Bxg2 and Qh3.
This famous position shows a fairly similar idea, but using interference rather than deflection to threaten the same checkmate:
You’ll probably recognise this as Fischer – Benko US Championship 1963, where Bobby spotted that the immediate e5 would be met by f5, so played 19. Rf6! instead, blocking the f-pawn, and preparing to meet Bxf6 with e5. Of course this idea will only work if you want to stop the f-pawn moving two squares.
While thinking about what to write this week I came across this position:
This is Averbakh (who celebrated his 99th birthday earlier this year) – Sterner Dresden 1956. Just as in my game, White wants to threaten mate on h7, but the immediate 25. Qe4 would allow 25.. Nxf6 26. exf6 g6, so he might have played 25. Rxg7 Bxg7 26. Qe4 instead. Instead of deflecting a pawn (my game) or interfering with a pawn (Fischer’s game) this is replacing the pawn with a bishop which is unable to advance. The same intention, but a different tactical device in each case. I’m not quite sure what you’d call this: perhaps you can advise me.
In fact 25. Qe4 Nxf6 26. exf6 g6 27. hxg6 fxg6 28. Rxg6 hxg6 29. Qxg6 with Kg2 and Rh1 to follow would also win quickly.
Averbakh chose neither of those moves, but 25. h6, although less accurate, was still good enough to win, with some help from his opponent, a few moves later.
It’s partly about pattern recognition, but also about awareness of a wide range of tactical ideas. In each of these positions one player wanted to set up a bishop and queen battery attacking h2/h7, but needed to get rid of an enemy pawn which could block the diagonal. I could have sacrificed to deflect the pawn to an adjacent file. Averbakh could have sacrificed to replace the pawn with a piece unable to move forwards, and Fischer did indeed sacrifice to block the square the black pawn would have to cross.
It’s worth remembering these ideas: you never know when you might want to use them.