Rook vs. Bishop

A Technical Endgame

When I reached this position yesterday, I was about a minute behind on the clock in a game where I had difficulty getting an advantage against a much lower rated opponent. Only when he walked into a knight fork that gave him a choice of losing a bishop or the exchange did the game seem to be going my way. I had White.

White to move

31.Nxf4+! Bxf4

31...Kf6 32.Kb3 Nd1 33.Nd3 might have forced me to work harder.

32.Kxb2 Kf6 33.f3

While reviewing the game, I thought this move was an unnecessary loss of tempo. The pawn can move when g4 is attacked. Better, it seems to me was to create some threats with my rook. Even so, this is not so easy, For instance, 33.Rh8 b6 34.Rc8 c5 35.Ra8 a5 and I'm not sure how to proceed.

33...b6 34.Kb3 a5 35.Rh8 Ke7 36.Rc8 Kd7 37.Rf8 Ke7 38.Rg8 Kf6

White to move

39.Ka4

39.c5 b5 40.Rc8 seems better. I have been moving fast, too fast and still have 5 minutes remaining in a ten minute game.

39...Ke7 40.Rh8 Kd7 41.Rh5 Be3

White to move

42.Rf5

42.c5! Bxc5 43.Rxc5 bxc5 creates a nice problem position.

White to move

Analysis diagram

 44.c4 (44.Kxa5??=).

42...Ke6 43.Rh5 f6 44.Rh8 Kd7 45.Rh7+ Kd6 46.Rf7 Bg5 47.f4 Bh4

White to move

48.f5?!

48.Rh7 Bg3 49.g5 b5+ 50.cxb5 cxb5+ 51.Kxa5 and White is making some progress.

48...Bg5

48...Kc5 49.Kb3

49.Rf8 Kd7 50.Rb8 Kc7 51.Re8 Kd7 52.Re6 Kc7

White to move

53.c5

It finally feels as though I am making some progress. I have 3:30 left and my opponent has 4:42.

53...bxc5

Black spent 19 seconds on this move.

54.Kxa5 Kd7 55.Kb6 c4 56.Rxc6 Be3+ 57.Kb7 Bg5 58.Rxc4 Kd6

White to move

59.Re4

My plan is to leave the c-pawn as a threat that must be stopped while the rook and king force Black's bishop and pawn off the board and one of my kingside pawns promotes. So, first, Black's king must be cut off.

59...Kd5 60.Re6 Kc4 61.Kc7 Kd5 62.Kd7 Kc5 63.Ke7 Kd5

White to move

64.Kf7 Bh4 65.Rxf6 Ke5 66.Rc6 Kf4 67.Rc4+ Kg5 68.Kg7 Bg3

White to move

69.Re4

The immediate f6 was possible because the pin is met by another pin. 69...Be5 70.Rc5.

69...Bd6 70.c4 Bc5 71.Kf7 Bb4 72.Rd4 Bc5 73.Rd5 Ba3 74.c5 Kxg4 75.c6 Black resigned 1–0

My play was less that perfect, but good enough.

One from Cozio

Position 132

Carlo Cozio (c. 1715 -- c. 1780) is best known for a book published in two volumes, Il Giuoco degli Scacchi o sia Nuova idea di attacchi, difese e partiti del Giuoco degli Scacchi (1766), and for an offbeat variation for Black against the Spanish opening. An original of his book is dated 1740, and was in the collection of Lothar Schmid, according to A. J. Roycroft in his article, "Cozio!, Part I", in the magazine EG (July 1973). Roycroft asserts, "occasionally the play is either atrocious or incomprehensible." Nonetheless, some of his work has been deemed to be of value. Roycroft published 9 of Cozio's studies in Test Tube Chess: A Comprehensive Introduction to the Chess Endgame Study (1972) and 18 more in his article in EG.

After a game that I played yesterday, I went looking in Yuri Averbakh, Rook v. Minor Piece Endings (1978) for some guidance regarding my errors. The position Averbakh gives is credited to Cozio.

After reaching an endgame of bishop vs. rook and pawn that I thought I could draw, I managed to throw the draw away no less than ten times in 31 moves. I drew because my opponent did not know how to exploit my errors. More likely, neither of us recognized the errors for the blunders that they are.

White to move

This position, which occurred in my game yesterday, is identical to Cozio's number 132 as it appears in Harold van der Heijden, Endgame Study Database VI (2020). If you read the Italian in the screenshot above, you will see that it mirrors diagonally the one in Cozio's text, but changes nothing vital. Colors are reversed and the defending king is in in the opposite corner. In Averbakh's book, Cozio's colors are maintained with Black defending, but the position is flipped vertically.

White's defense is relatively simple. Keep the bishop on the b8-h2 diagonal. Averbakh makes this technique clear. I had been reading this book last week, preparing lessons for my students on rook vs. bishop endgames, but had not yet gotten to the point where Cozio's study is presented (28). Otherwise, I would have known what I was doing. However, my confidence that I could draw stemmed from this study and practice with my students of similar endings--rook vs bishop without a pawn.  I reasoned correctly that a rook pawn did not change much. After some unfavorable developments, I raced my king to the "safe corner". My opponent should have prevented this journey.

77.Bc7 Kf3 78.Bb6??

78.Bb8 or 78.Kg1 hold the draw.

78...Rf1+ 79.Kh2

Black to move

79...Rb1??

79...Rc1 is the only move that wins here. Black must understand White's defensive idea and prevent the bishop's return to the critical diagonal. The direct attack on the bishop forces the bishop back where it belongs.

80.Bc7 Kg4 81.Bd6 Rf1 82.Bc7 Rf2+ 83.Kh1

We have returned to the position after my 77th move.

83...Rg2 84.Bd6 Kf3 85.Bc5??

This was the ninth time that my bishop wandered away from its duties.

85...Ke2 86.Bb6??

The tenth and last.

Black to move

86...Kf1

Again, Black should have prevented the bishop's immediate return to the correct diagonal with 86...Rg7.

87.Bc5

Knowing what I do now, I would play 87.Bc7. But in this position, it is not critical. Black's king should be seeking to go to h3 after the pawn advances. That becomes possible if I keep leaving the key diagonal.

87...Rc2 88.Bb6 Rg2 and the game was drawn by repetition.

The moves Cozio gives in his book are less instructive, but he keeps the bishop on the correct diagonal.

White to move

1.Rc8+ Ka7 2.Rc7+ Ka8 3.Kb5 Bd4 4.Kc6 Be3 5.a7 Bxa7 6.Rc8 Bb8

We reach a position that I have been teaching to my students the past two weeks.

White to move

7.Rh8 Ka7 8.Kb5 Ka8

White cannot make progress.

9.Kb6 Stalemate.

Rook versus Bishop

When I think that I understand something, I expect to be able to execute the maneuver in mere seconds. Sometimes, my understanding of the patterns is not strong enough. It is well-known that rook versus bishop is usually a draw, but that a few positions favor the rook. One such position is an exercise in my Essential Tactics: Building a Foundation for Chess Skill (2017).

White to move

The tactic is simple. 1.Kf6, forcing the bishop to move. But then, the finish takes me more time than I think it ought. I want to execute the moves to checkmate in ten seconds or less, but find that the calculation can require a minute or more. Each White move must contain a concrete threat of a) checkmate, b) capture of the bishop, or c) the final threat that pins the bishop on the back rank, creating zugzwang. One slip and a drawn bishop versus rook ending is reached.

In rare instances, usually with more pieces on the board, the bishop dominates the rook. This composed problem came to my notice via Mikhail Tal, and Victor Khenkin, Tal's Winning Chess Combinations (1979).

White to move

White need only check the king from a square where the bishop cannot be captured. Alas, both the immediate 1.Bh3 and 1.Bg4 fail. A zwischenzug is necessary to divert the rook from control of these squares.