The full game can be seen at K2 but here I want to focus on the ending.
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| Black has just captured on d7 - how would you assess this ending? |
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For the second game running, I have reached a rook-and-bishop ending. White has kingside weaknesses and will find it difficult creating a passed pawn from his majority, while Black's queenside majority has no such drawbacks. Komodo12.1.1 reckons Black is slightly better, but Stockfish14.1's verdict is equality. Looking at the position again, I guess White does have something Black is lacking, ie a central pawn, but it is probably fair to say only two results are likely, barring blunders: a draw or a black win.
20.Rg1
20.Rd1?! Rxd1 21.Kxd1 gives the kings more freedom, which would make White's pawn weaknesses more vulnerable.
20...Ke6
Centralising the king is normally a priority in endings, but here the engines slightly prefer 20...Rd5!?, introducing the threat of ...Rh5.
21.e4
Gaining space in the centre, but weakening the f4 square. The engines slightly prefer 21.h4!?, gaining space on the kingside.
21...Bd6 22.h3
Black could not safely capture the white h pawn, but it will probably have to be moved sometime, although again the engines prefer h4.
22...c5
Activating the queenside pawn majority is Black's long-term plan, but at this point the engines like 22...Bf4.
23.a4?!
Hoping to slow the black queenside pawns, but the text weakens the white queenside. The engines still like h4.
23...Be5 24.Rc1!?
On 24.Bxe5 I intended 24...Kxe5, and if 25.Ke3 then 25...g5, when the white pawn weaknesses give Black good winning chances despite it being a rook-and-pawn ending with equal material. As usual, instead of Rc1 the engines recommend h4. One reason they do not like the text is that if Black exchanges on c3, they want White to recapture with the b pawn, as will be seen later.
24...b6 25.b3?!
White should have retained the option of meeting ...Bxc3 with bxc3. True, White would get two isolanis, but more important is the fact that split white pawns make it harder for Black to activate his majority.
25...Bxc3!
Swopping into a rook-and-pawn ending is the strongest option, according to the engines.
26.Rxc3
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| How much better is Black? |
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White's weak h pawn, doubled f pawns and difficulties creating a passer to match Black's coming passer on the queenside mean Black is winning, according to Stockfish14.1, although Komodo12.1.1 'only' gives Black the upper hand.
26...Ke5 27.a5
If 27.Ke3 then 27...g5.
27...f5 28.axb6 axb6 29.Re3
29.Ke3 f4+! 30.Ke2 leaves White with a protected passed pawn that would be strong in a pawn ending, but the engines reckon 30...Ra7! is very good for Black, eg 31.Rc2 Ra3 32.Rc3 (32.Rb2 Kd4) Ra2+ 34.Ke2! (34.Kg2 cuts the king off from the queenside) 34...Ra2+ (34...Rh1 also probably wins) 35.Kf1 Kd6 etc.
29...Rd6 30.exf5+
White was effectively in zugzwang, eg 30.Ke1 Rd4 forces exf5+ but with the white king less-centrally placed.
30...Kxf5 31.Re4
Komodo12.1.1 suggests 31.b4!?, but Black is on top after 31...c4 or 31...bxc4.
31...g5?
This gives White serious drawing chances, whereas 31...Rd4, 31...b5 and 31...Re6 maintain Black's large advantage.
32.h4?
At last h4 is played, but by now it is a mistake that makes Black's win easier. Correct is 32.b4, which the engines reckon effectively equalises, eg 32...Re6 33.bxc5 bxc5 34.Kd3 Rc6 35.Rc4, when Black cannot make progress.
32...Re6 33.Kd3
This is best. After 33.Rxe6 Kxe6 34.hxg5 Kf5 Black will get a passed pawn on both sides of the board.
33...b5?!
Simple and good is 33...Rxe4 34.fxe4+ Kf4 35.hxg5 (35.f3 gxh4; 35.h5 g4) Kxg5. True, 36.f3 gives White a protected passed pawn but the white king cannot cope with Black passers on both sides of the board.
34.Rg4 h6 35.hxg5 hxg5 36.Kd2 Rd6+ 37.Ke2 Rd4 38.Rxd4?
This loses trivially, so White had to try 38.Rg1. After 38...Rb4 the passive 39.Rb1? also loses fairly trivially, to 39...c4, so necessary is the active 39.Rc1 c4 40.bxc4, which seems to draw.
38...cxd4 39.Kd3 Kf4 0-1
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