A Misplayed Ending

I MISPLAYED a fairly straightforward bishop-and-pawn ending in my round-four game at Mariánské Lázně.

The full game can be seen at ML 4 but here I want to concentrate on what went wrong in the ending.

White has just captured on f2

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White has more space but has an extra pawn-island, The black bishop is well-placed but the black queenside pawns could become targets for the white bishop. The analysis engines Stockfish14.1 and Komodo12.1.1 reckon the position is dead-equal.

34...Bc2

Stockfish14.1 likes 34...b5 even though Black has to beware the vulnerability of a6 after 35.a5.

Komodo12.1.1 recommends 34...f5!?, which supports the bishop but puts another pawn on a light square. Stockfish14.1 reckons the reply 35.a5 gives White a tiny edge.

35.a5 Be4 36.h4 h5?!

Space is important in endings but here it was almost certainly more important to avoid putting more pawns on light squares.

37.Be2 g6

An unfortunate consequence of the previous move, but 37...Bg6? is worse, eg 38.Kf3 Kd6 39.e4 f6 40.Kf4 Ke7 41.Bc4 Kd7 42.e5 Ke7 43.d5 fxe5+ 44.Kxe5 Kd7 (44...Bf7 45.d6+) 45.d6 Bc2 46.Be6+ Kd8 47.Kd4 with Kc5-b6 etc to come.

38.Bf3

Position after 38.Bf3

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38...Bd5?

Black seems to hold after 38...Bxf3, eg 39.gxf3 f6! (an only-move, according to the engines) 40.e4 g5! (another only-move) 41.e5 Ke6, or 39.Kxf3 f5! (only-move) 40.Kf4 Kf6 (an only-move, but an obvious one) 41.g3 Ke6 42.Kg5 Kf7.

39.e4 Be6 40.Ke3 Kd6 41.Kf4 Bc4 42.Kg5

Neatly illustrating another problem with having all pawns on the same colour-complex as the bishop - the other-coloured squares become vulnerable to a king invasion.

42...Be6 43.Kf6 Bc4 44.g3 Bb3 45.g4

This was also strong on the previous move.

45...hxg4 46.Bxg4 Ba2

Or 46...Bc4 47.e5+ Kc7 (47...Kd5 48.Kxf7 Kxd4+ 49.e6 etc) 48.Ke7 Bd5 49.Bd7 etc.

47.e5+ Kd5 48.e6 1-0

CONCLUSION: positional mistakes in middlegames can often be corrected in time or masked in the hurly-burly of tactics, but positional mistakes in endings tend to be permanent and are the reason why the difference between masters and club players can be starkest in an endgame.