Saturday, February 16, 2013

Postcard from Delhi

Adarsh Jayakumar, on the hunt for his final International Master norm, played in international events in Chennai and Delhi last month. I think it would be easier to pick up an IM norm in Europe than in the land of 1.2 billion fans of Vishy Anand. Adarsh dropped a few points on the trip, but he had some very interesting games, and he kindly sent a few of them with notes.

In the general case, two bishops are much better than two knights when each side has five pawns or fewer. And as pawns get exchanged, the long-range bishops get more scope grow in power.  But if the player has the two knights has an extra pawn, the ending is bound to be nerve-wracking.

In pawnless endings, two bishops are theoretically able to evict the knight from a blockade position. In a tournament game, the fifty-move rule comes into play.


2 comments:

Frederick Rhine said...

Two bishops versus one knight is very difficult to win if the defender plays correctly. For centuries, it was thought to be a draw, until computers proved otherwise around 1990. Timman-Speelman, Linares 1992 (http://www.chessgames.com/perl/chessgame?gid=1130375) may have been the first game in which the players during the adjournment had access to the computer analysis of the ending. Timman wrote in his games collection that he still had trouble getting the hang of it. The best defensive setup is to have your knight on one of the "N2" squares (b2, g2, b7, g7) with your king hovering outside it (for example, N on b7, king moving between b6 and c7). If your opponent manages to break down that semi-fortress, pack your bags and move to another N2 square. Popovic-Korchnoi, Sarajevo 1984 is a good example of successful defense. Play it out from move 70 on - http://www.chessgames.com/perl/chessgame?gid=1082846. I was surprised to see that the superior side managed to win 10 out of 19 of the games with this ending in chessgames.com's database - http://www.chessgames.com/perl/chessending?s=BB&i=N&result=*.

Bill Brock said...

Whatever the theoretical result, I think White's practical chances after Adarsh's suggested 66... Nfd4! 67. Kb6 Nb4 68. Bg3+! Ke6 69. Bc8+ Ke7 70. Bxg4 are excellent.

White does not have to win a knight immediately, as the 2Bs vs. N ending is probably a PRACTICAL draw wnen the defender can reach one of the corner setups described by Frederick above.

But White can always choose when to push the a-pawn and win a knight, and can try for a Richard III win ("my kingdom for a horse") by separating defending king and knight. The Tal-Botvinnik 1961 game is a good example.