Knight v Bishop (part 18)

THERE were 17 bishop-v-knight endings from my praxis that began with seven pawns aside but did not end in draws. The knight's side won nine times.

I now move to bishop-v-knight endings from my praxis that began with six pawns aside but did not end in draws.

Black has just captured on g5 in Tom Musgrave (?) - Spanton (-), Doncaster & District Swiss 1980. Who stands better, and by how much?

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The analysis engines Stockfish12 and Komodo11.01 reckon the position is dead-equal.

34.Nf4 Bd2?

This lets the knight enter the black position and get at the black pawns. The simple 34...Kf6 is among several moves maintaining equality.

35.Ne6+ Kh4?!

The engines much prefer defending the kingside with 35...Kf6. After 36.Nd8 and Nxb7, White is a pawn up but there is a long way to go before that can be converted into a win.

36.Nxg7 Kxh3 37.Nf5

Black has not yet lost a pawn, but the black king is sidelined and the white knight cannot be stopped from raiding the queenside.

37...Bc1 38.b3

The engines' 38.b4!, overprotecting c5, is better, as will become clear.

38...Kh2

The engines give 38...a6!, covering b5. Then 39.Nd6 Bb2 40.Nxb7 Bxd4 requires White to play 41.b4 (this is why 38.b4! is better than 38.b3, even though it puts a pawn on the same colour complex as the bishop). Then 41...Bc3 42.a3 Bb2 43.a4 Bc3 is level. It may be that 43.Nd8 Bxa3 44.Nxc6 is an improvement for White, but 38...a6 is Black's best chance.

39.Nd6 Bb2 40.Nxb7 Bxd4 41.b4 Bc3 42.a3 Bb2 43.a4 d4

If 43...Bc3, White has 44.b5, which would not be so strong if Black had played 38...a6!

The game finished:

44.Na5 d3 45.Nc4 Bc3 46.b5 cxb5 47.axb5 d2 48.Kd2 d1=Q+ 49.Kxd1 Kg3 50.c6 Kxg4 51.c7 h5 52.c8=Q+ Kg5 53.Qg8+ Kh6 54.Qe6+ 1-0