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Subject: Re: Look at this !!(??) move by Crafty 18.14!

Author: Uri Blass

Date: 08:44:46 03/27/02

Go up one level in this thread


On March 27, 2002 at 09:59:05, Robert Hyatt wrote:

>On March 27, 2002 at 07:18:09, Aaron Tay wrote:
>
>>On March 27, 2002 at 06:55:43, James T. Walker wrote:
>>
>>>On March 27, 2002 at 05:28:28, Jouni Uski wrote:
>>>
>>>>[D]8/B5pp/4k3/P7/6n1/8/P6P/7K b - - 0 41
>>>>
>>>>Crafty as black played Nxh2!!(??). Yes the game ended draw so the move is
>>>>probably correct, but I doubt, that Crafty's evaluation really understand this.
>>>>E.g. if white plays a6 then black has no way to a8 square...
>>>
>>>*******
>>>You can't have it both ways!  If the move is correct then a6 means nothing.  If
>>>a6 wins then Nxh2 is definitely wrong.  Can you prove that a6 wins?  Crafty is
>>>counting on the Bishop not covering the a8 square I guess.  But this could be
>>>one of the exceptions to the rule if you can prove that a6 wins.  The black King
>>>must head for c7/c8 so it can get to b8 then a8 if the Bishop moves.  I suspect
>>>it all hangs on a tempo.  How is the lone King to stop the two connected passed
>>>pawns without moveing the Bishop?
>>>********
>>
>>[D]8/B7/4k3/P7/6n1/8/P6P/7K b KQkq -
>>
>>Remove black's 2 passed pawns and it still thinks Nxh2 is good with a near draw
>>score..Eventually (21 seconds on mine,depth 18) crafty 18.13 sees the loss after
>>Nxh2 but there is nothing better..
>>
>>I guess the rule does have a problem..
>>
>>
>>Aaron
>
>Mine doesn't play Nh2 in the above position.  This now becomes a zugzwang
>position with no black pawns to move, which turns it into a trivial mate for
>white...

I guess that it does not play Nxh2 because of tablebases.

I wonder what happens when  you add a third pawn for white in the a file.

Uri



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