Monday, February 16, 2015

Bent Larsen’s Best King and Pawn Endgames: The Square

White to play
Larsen - Uhlmann, Candidates’ Quarter-Final match (9) 1971

Here’s a critical decision for Bent Larsen. Black has just played 58 ... Ke5. Does White swap bishop for knight or not?

If our hero gets this decision right he’ll win not just the game but the match too. Balls it up and he’ll have to play the final game needing a draw to go through.

What would you do? For those that want it, the answer  can be found after the jump.

White to play
Larsen - Haik, Lanzerote 1976

This is another one of Bent Larsen’s Best Games. White’s a couple of pawns up. How’s he going to win? Answer: with 40 b5! axb5, 41 a6 and now it’s time to resign.


Black must play 41 ... Kc6 to stay in the square of the pawn, but White answers with 42 d5. Capturing the d-pawn means stepping out of the square of the a-pawn so 42 ... Kc7 but White keeps advancing anyway. Push the pawn to d6, then d7. Eventually it will queen and Black will have to take it, but that leaves nothing to stop the a-pawn going all the way.

So, back to Larsen’s Candidates’ match with Uhlmann.

With Larsen - Haik in mind, how about 59 Bxd6 Kxd6, 60 Kf4 Kd5, 61 b5?

61 b5

When I first looked at this game I’d wanted to go 61 Ke3 Ke5, 62 b5 +- instead. Unfortunately, while Ke3 wins against ... Ke5 and ... Kc4 I’d overlooked that Black can simply push his h-pawn so Larsen’s pawn sacrifice is absolutely necessary. Necessary, but entirely sufficient.

61 b5 axb5, 62 a6 Kc6, 63 Kxe4 b4, 64 f4 and at this point Uhlmann surrendered.


The kings are in the squares of their respective pawns, but White's f-pawn is going to be quicker than Black’s h-pawn. There’s still one more trick in the position to watch out for - dragging the king to the back rank so you can queen with check - but this game is over.

And there you have it: a Candidates’ match decided by the use of the most basic king and pawn endgame technique there is.


Jonathan Rogers said...

It's a cute one, because Black can, after f4, immediately play b3-b2-b1, hoping to queen his h-pawn with check against Kb1. That would draw if White just advances his f-pawn. But White instead does the same thing - a7-a8, and then he queens with check on f8 first! I don't remember seeing this theme arise for both sides before.

Anonymous said...

Can you tell me please what chess GUI are you using in this diagrams?

Jonathan B said...

SCID vs Mac

Anonymous said...