Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Testposition - Bishop ending

Author: Oliver Roese

Date: 15:38:16 04/24/02

Go up one level in this thread


On April 24, 2002 at 17:00:09, Sune Larsson wrote:

>On April 24, 2002 at 15:46:11, Oliver Roese wrote:
>
>>Hi!
>>
>>On April 24, 2002 at 13:34:21, Sune Larsson wrote:
>>
>>>
>>> [D]8/2b1Bp1k/2p3pP/4P1P1/2P1K3/8/8/8 w - - 0 52
>>>
>>> Every program I've tried so far seems to think that this position
>>> is won for white. There are evals of more than +3.00. White is a pawn
>>> up but it's a dead draw.
>>>
>>> White's king has three doorways to heaven, a5, c5 and e5.
>>> But black's bishop is closing everyone of them:
>>>
>>> 1) The white king moves to a4 and tries to enter via a5.
>>>    Black keeps the bishop on c7 and shuffles the king.
>>>
>>> 2) The white king moves to b4 or d4 and tries to enter via c5.
>>>    Black puts the bishop on b6.
>>>
>>I am sorry to oppose but here is the weak point. Lets assume this position would
>>arise:
>>[D]6k1/5p2/1bp2BpP/4P1P1/1KP5/8/8/8 w - - 0 1
>>White breaks through and gives his pawn e5 for pawn c6. Two passers
>>are enough to win, e.g::
>>1.Be7 Kh7 2.Bc5 Bd8 3.Be3 Bc7 4.Kc5 Bxe5 5.Kxc6 and white wins easily.
>>
>>Oliver Roese
>
>
>
> [D]6k1/5p2/1bp2BpP/4P1P1/2P5/1K6/8/8 b - - 0 1
>
>
> Before the white king reaches b4, black must play 1.-Ba5! keeping
> the resource 2.-Bd2! =
>
> Sune

You are right, that's it.
I couldn't find another idea to win, so it seems this position is a draw.
Pretty amazing, i think.
Where does this position come from?
Oliver


>>
>>
>>> 3) All the time black prevents the possibility 1.e6 fxe6 2.Ke5
>>>    by keeping the bishop on c7.
>>>
>>> 4) If white plays his bishop to f4, threatening 1.e6 black plays
>>>    1.-Bb6. Then 2.e6 fxe6 3.Ke5 is met by Bc7+
>>>
>>> 5) And black has a million of Kg8-h7 moves while white cannot make
>>>    any progress at all. 1.Bd6 Bd8 is nothing. All c5 moves from white
>>>    are just voluntarily closing one possible path for the king.
>>>



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.