Knight v Bishop (part 22)

Black has just captured on e7 in Spanton (151) - Julien Shepley (163), Barbican (London) Rapid 1989. Who stands better, and by how much?

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Rival pawn-majorities favour the bishop, but that is the only major factor to Black's advantage. The bishop has no real targets (h2 is easily defended, and hard to get at), while the fixed nature of the queenside pawns will make the black ones vulnerable if the knight can get at them. In addition White has a protected passed pawn, meaning an exchange of minor pieces will almost always be hopeless for Black. Stockfish12 reckons White is winning, but Komodo11.01 gives White only a slight edge.

32.Kf3!?

Komodo11.01 is happy with this but Stockfish12 strongly dislikes it, preferring 32.g4, which gets a white pawn off the same coloured square as the bishop as well as gaining kingside space. Certainly White should not fear 32...f5?! as 33.gxf5 gxf5 34.Nf4 is good for White.

After the text, Stockfish12 reckons White only has a slight edge, but Komodo11.01 now reckons White has the upper hand.

32...f5 33.Kf4 Kf6 34.h3

The engines prefer 34.h4!? One point is that fixing White's kingside pawns with 34...h5? runs into 35.d6! Ke6 36.Kg5 etc.

34...g5+

The engines reckon 34...Be5+!? draws, eg 35.Kf3 Bd6 36.g4 h6 37.gxf5 Kxf5 38.Nf2 Bf8 39.Ne4 h5, when it is hard to see how White makes progress.

35.Kf3 h5!?

The engines strongly dislike this, preferring 35...Ke7 or 35...Bg1, but is far from clear they are correct.

36.Nf2

Komodo11.01 gives 36.h4 g4+ 37.Kf4, claiming White is winning. But after 37...Bc3 38.Ke3 (Black threatened 38...Bd2#) Bd4+ 39.Ke2 Be5 White has nothing better than 40.Nxe5 Kxe5 41.Ke3, when Stockfish12 is right to evaluate 41...f4+! 42.gxf4 Kf5 as a draw. Komodo11.01 still claims White is winning, but the mutual protected passed pawns mean neither side can make progress.

36...Be5 37.Nd3 Bd6 38.Kf2 h4?!

Black creates a passed pawn, but after ...

39.gxh4 gxh4

... the white king can advance, and h4 becomes a fixed target.

40.Kf3 Kg5 41.Nf2 Kg6 42.Nd3 Kf6

The engines reckon the text and 42...Kg5 are equally strong, with White having a slight edge in either case. The latter move can be met by 43.Kf3 Kf6 44.Nf4 with play similar to the game.

43.Nf4 Kg5 44.Ne6+ Kg6?

Correct is 44...Kf6, and if, as in the game, 45.Nd8 Bc7 46.Nb7 Bb6 then 47.d6!? does not win as Black simply replies 47...Ke6.

45.Nd8 Bc7 46.Nb7 Bb6 47.d6! Kf7 48.d7 Ke7 49.d8=Q+ Bxd8 50.Nxd8 Kxd8

Black is temporarily a pawn up, but is lost.

The game finished:

51.Kf4 a4!? 

Or 51...Kd7 52.Kxf5 Kd6 53.Kf6 Kd7 54.Ke5 etc.

52.Kxf5 axb3 53.axb3 Kd7 54.Kg4 Ke6 55.Kxh4 Ke5 56.Kg5 Kd4 57.h4 Kc3 58.h5 Kxb3 59.h6 Kxc4 60.h7 b3 61.h8=Q Kb4 62.Kf4 c4 63.Ke3 c3 64.Qd4+ Ka3 65.Qxc3 Ka2 66.Qa5+ Kb2 67.Kd2 Kb1 68.Qc3 b2 69.Qc2+ Ka1 70.Qa4+ Kb1 71.Kc3 Kc1 72.Qc2#