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Subject: Re: hard? opposite bishops ending

Author: Robin Smith

Date: 14:33:12 09/21/01

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On September 21, 2001 at 11:43:50, Simon Finn wrote:

>On September 20, 2001 at 21:08:07, Robin Smith wrote:
>
>>On September 20, 2001 at 13:00:17, Roy Eassa wrote:
>>
>>>On September 19, 2001 at 01:10:00, Robin Smith wrote:
>>>
>>>>Can any programs solve this ending?
>>>>
>>>>[D] k7/8/4p3/7P/8/3P4/1Bb4P/K7 w - - 0 1
>>>>
>>>>Kazantsev, 1950 study
>>>>
>>>>Solution: 1.Bh8!
>>>
>>>
>>>Could somebody please explain why Bh8 is the only way to win?  What's the
>>>winning plan?
>>
>>Black has a strong defensive plan.  If black gets his king in front of the
>>h-pawns, blockading them, and his bishop to a square that defends the e-pawn,
>>white will not be able to make progress.  So white MUST prevent this.
>>
>>The only way to prevent this defensive plan is to get the white king to g7 as
>>quickly as possible, keeping black's king away.  Thus the first moves of the
>>main line go:
>>
>>1.Bh8! Kb7 2.Kb2 Bxd3 3.Kc3 Bf5 4.Kd4 Kc6 5.Ke5 Kd7 6.Kf6 Ke8 7.Kg7
>>
>>Once white has the king on g7, the next step is to march the forward h-pawn up
>>the board, threaten to queen, and force black to give up his bishop for it.
>>White then queens the remaining h-pawn.  Meanwhile white's bishop prevents black
>>from queening the e-pawn.
>
>So why doesn't 1. Bc1 also work?
>
>1. Bc1 Bxd3 2. Kb2 Kb7 3. Kc3 Bb1 4. Kd4 Kc6 5. Ke5 looks winning.
>
>Black can try to block the White king's progress with ...e5, but
>White can just go round the pawn:
>
>1. Bc1 Bxd3 2. Kb2 e5 3. Kc3 Bb1 4. Kc4 Kb7 5. Kd5 also looks sufficient.
>
>So what am I missing?
>
>Simon

I think after 1.Bc1? Bxd3 2.Kb2 e5 3.Kc3 Be4! (controlling the d5 square) and
white cannot break through.

Robin



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