Calculation

Some annotations in Chess Informant 129 brought home to me the level of calculation that is necessary in Grandmaster play. While running a local chess tournament last weekend, I spent some idle time reviewing an issue of Informant that I happened to have on the computer that I was using for pairings. I took this position into the skittles room for some participants to work on between rounds.

White to move

It is White's move 24, and SP Sethuraman, who won this game enroute to the Asian Championship, said that his opponent missed this tactic when playing a7-a5 three moves earlier.

Black to move

Sethuraman suggests 21...a6 22.e5 Nd5 23.Nxd5 cxd5 Qh5 "is given by the computer as equal, but I would prefer White here" (SP Sethuraman, "Through the Fire," Informant 129, 71).

After 21...a5 22.e5 Nd5 (22...Nd7 was played in the game) 23.Nxd5 cxd5, the b5 pawn is weak.

The game continued:

21...a5 22.e5 Nd7 23.Bf5 Nxe5 and we have the diagram at the top of this post, where Sethuraman played what he called a "cute little tactic" (71).