Sunday, 28 February 2010

Every tempo counts

The following position was reached in the first round of the ACT Championships. It is Black's move and the first decision is whether to go into a king and pawn ending with Rg1+. To make the correct call, Black needs to be able to calculate whether the ending is winning/drawn/lost. In positions like this counting tempo correctly is crucial.
Black decided to play 43. ... Rg1+ and after the forced 44.Qxg1 Rxg1+ 45.Kxg1 Kxd5 46.Kf2 he then had to decide how to clean up the a and b pawns. Meanwhile the spectators (including me) had come to the conclusion that Black now wins by a tempo with 46. ... Kc4 47.Kf3 Kb3 48.Kf4 Kxb2 Turns out we were horribly wrong as White is winning by a tempo in this position. However Black was a little smarter than we were as he grabbed the a pawn with 48. ... Kxa4 (instead of 48. ... Kxb2) and after 49.Kxf5 Kb3 50.Kg5 Kxb2 51.Kxh5 a5 52.Kg6 a4 53.h5 a3 54.h6 a2 55.h7 a1(Q) 56.h8(Q)+ Kb1 57.Qxa1+ the game was drawn.
However, the post mortem revealed how tricky these endings really are, as White missed a win with 48.a5! forcing Black to take an extra move to capture the a pawn, and losing by a tempo. And if 48.a5! was good for White, it turned out that 46. ... a5! was just as good for Black, when Black ignores the queenside pawns and instead shepherds the f pawn up the board instead!


Anonymous said...

48.a5 may win, but that is only because Black played 47...Kb3?? instead of the normal 47...Kb4.

Paul said...

Nice one !

Anonymous said...

does anyone know when the pairngs are going to be out for the next round in the ACT Championship.