6

Consider the following position:

Bishops checkmate

What are the possibilities for checkmating the white king within 16 moves?

BlueBerry - Vignesh4303
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  • Where's the black king? It could be critical. – Tony Ennis Jul 29 '12 at 15:30
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    I went ahead and edited in the position of the black king as h1. – ETD Jul 29 '12 at 18:57
  • well there s an mate at 15 the move i hope you will guess it,hopes to get more winning combinations – BlueBerry - Vignesh4303 Jul 30 '12 at 19:36
  • vignesh, welcome to the Chess beta. Is there something particular that you're trying to learn from (or about) the position in your question? It's not clear (to me at least) what sort of information you're seeking to get from answers. – ETD Jul 31 '12 at 08:17
  • @EdDean sir thanks for welcome i mated the white king within 16 moves in an friendly match. i hope to get more winning combinations for checkmating it withing 16 moves(notably i have one winning combination i post it soon) – BlueBerry - Vignesh4303 Jul 31 '12 at 08:20
  • -1: Consult a tablebase if you really want to know. There is little to be gained by asking humans about this. – Evan Harper Aug 01 '12 at 03:56
  • @EvanHarper even though tablebases were created based on human's past moves in tournament, – BlueBerry - Vignesh4303 Aug 01 '12 at 17:17
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    No, they weren't. Tablebases are mathematical solutions to endgames compiled by exhaustive computer searches. Tournament moves have nothing to do with it. – Evan Harper Aug 01 '12 at 21:03

3 Answers3

7

This likely is not the answer you are looking for, but Jerry (A 2200+ USCF National Master) from the Chess Network has a nice video explaining the algorithmic approach to checkmate with two bishops. I think it solves your problem in less than 25 moves.

http://www.youtube.com/watch?v=uimbIq9h_7A

EPN
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6

Endgame tablebases, which you can find at this website, will assure you that there is no placement of the Black King such that White can hang on for longer than sixteen moves if given the right to move first.

David Spencer
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When I put the black K at h1, which seems fairly worst-case, Stockfish says mate in 16. This doesn't necessarily mean it's the fastest way, or even completely accurate; chess engines without end-game tables can be very awful.

Here's the solution. Good chance of being accurate ;-)

[FEN "3K4/8/8/8/3b4/3b4/8/7k b - - 0 1"]

1. ... Kg2 2. Ke7 Bc4 3. Kd6 Kg3 4. Kc6 Kf4 5. Kd6 Bf2
6. Kc6 Ke5 7. Kd7 Bb5+ 8. Ke7 Bh4+ 9. Kf7 Kf5 10. Kg7 Bg5
11. Kf7 Bf6 12. Kg8 Kg6 13. Kf8 Bg5 14. Kg8 Bh6 15. Kh8 Bg7+
16. Kg8 Bc4#

Again, I started the black K on h1.

I am not surprised. Consider that the K needs 8 moves to get all the way across the board. The adjacent bishops might need 8 more. That's 16, so 9 moves remain for rearranging pieces. No sweat. B+N is harder.

Tony Ennis
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