An unexamined life is not worth living.

Wednesday, May 27, 2009

Opposite Coloured Bishops – part 1

This begins the series of posts based on one of my articles that was published in En Passant, the Canadian chess magazine. I made little changes to the original contents, and just converted each example into a separate blog post.

When people talk about endgames they are often not sure what exactly is meant by this term. Sometimes any position without queens is called an endgame. A more sophisticated approach is to look at the role of kings. If the king can play an active role in the game without serious risk, usually this is called an endgame. And yet there are exceptions to this definition. To clarify the terminology, a famous coach M. Dvoretsky introduced the concept of 'simple positions', where one of the type of pieces is absent - either rooks, queens or minor pieces. Understanding simple positions is often more important than knowing precise theoretical positions. The most common type of simple positions is rook+minor piece vs. rook+minor piece. I would like to mainly deal with one type of such positions, where each side has a rook + bishop, with the bishops of opposite colours. We will also need to explore the endings with only bishops of opposite colours.

(1) Jiganchine R - Baryshev
Moscow team ch (4), 15.02.1998

opposite_bishop_85

28.Rb1 Here I naively expected either a draw offer, or a simplification of the position. In fact, Black has some advantage: his rooks have open files against my pawns; his bishop is more active than mine. 28...Rfc8 29.Be4 Rc5 30.Ra1 Ra5 31.a4 ? 31...bxa3 32.Rxa3 Rxa3 33.bxa3 Rb1+ 34.Kg2 Ra1 35.Rd3 Ra2 36.Rb3 a5 Diagram

opposite_bishop_86

I failed to find any plan, and allowed my opponent to invade with his rook. My pieces are so uncoordinated that I cannot save a pawn. 37.Rb8+ Kg7 38.Rb3 a4 39.Rf3 Bf4 40.h4 f6 41.hxg5 hxg5 42.Rf1 Rxa3 43.Bd3 Rc3 44.Ra1 a3 45.Kf3 Kf7 46.Ke2 Ke7 47.Kf3 Kd8 48.Ke2 Kc7 49.Kd1 Kb6 50.Rb1+ Ka5 51.Rb8 Rc5 52.Ra8+ Kb4 53.Rb8+ Ka4 54.c4 [54.Ra8+ Trading off rooks cannot save White: the 'a' pawn would cost me a bishop. 54...Ra5 55.Rxa5+ Kxa5 56.Bc4 Kb4 57.Ba2 Kc3-+] 54...dxc3 55.Bc2+ Ka5 56.Ra8+ Kb6 57.Rxa3 Rxd5+ 58.Ke1 Bd2+ 59.Kf1 Diagram

opposite_bishop_87

59...Rb5 ?? Just as I was considering timely resignation, here comes the amnesty. [59...Re5 after 60.Ra8 Re1+ 61.Kf2 Rc1 62.Bb3 Bf4 63.Rf8 Be5 White's counterplay against f6 is eliminated, and Black can start invading with his king.] 60.Rb3 ! Of course! After the exchange of rooks I can block the Black pawns. 60...Rxb3 61.Bxb3 Kc5 62.Ke2 Kd4 63.Bc2 d5 64.Bd3 Ke5 Diagram

opposite_bishop_88

65.Kf3 Ke5-f4 was threatened; Black's only hope is to win my g4 pawn, but this is impossible. 65...Bf4 66.Bb1 Kd4 67.Ke2 White established a fortress. 67...Kc4 68.Bc2 Kb4 69.Kd3 Be5 1/2-1/2 Black tried to win for another 30 moves, as I was low on time, but finally my claim for a draw was accepted.

A very instructive game. I remember being surprised twice: 1) when my opponent did not offer me a draw and then outplayed me. 2) when he allowed me to trade off rooks and then still thought he had a win.

Everybody has heard that endgames with bishops of opposite colours are drawish, because it is very often possible to set up a blockade on the squares of colour of one's own bishop. Then even a 2 or 3 pawn advantage can be insufficient for a win, just as in my game against Baryshev. Positional subtleties are usually more important than material. A defending side can sacrifice a pawn to set up a blockade or a fortress; a stronger side can sacrifice material to create a passed pawn or to get access to the opponent's weakness. Future posts will show some theoretical positions…

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