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Subject: Re: Stalemating swindle

Author: Uri Blass

Date: 21:55:28 11/27/02

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On November 27, 2002 at 23:45:47, Robert Hyatt wrote:

>On November 27, 2002 at 15:44:03, Alastair Scott wrote:
>
>>On November 27, 2002 at 10:44:12, Richard Pijl wrote:
>>
>>>I had special detection code for rambling rooks in the Baron, but removed that
>>>in 0.99.3 as it fired wrongly in certain cases. This means that Baron 0.99.4
>>>beta 1 doesn't find the draw.
>>>
>>>Baron 0.36 (containing the rambling rook detection code) has no problem
>>>detecting the draw, it spots it immediately, showing Kxe3 as the PV. When backup
>>>up to the diagram position it doesn't show the draw anymore. The reason is that
>>>Baron considers 60..gxh3 a mistake, enabling the draw. Instead, Baron 0.36 will
>>>play 60..Rge2!
>>>
>>>I have been thinking a lot about a better way to detect perpetual check's but
>>>haven't implemented anything yet.
>>
>>You're right - I saw Rge2 immediately after I played Rh3, but Ruffian never even
>>considered it.
>>
>>But Crafty 19.1 comes up with a remarkable shot after 33 seconds (at 14 ply) -
>>60..Rg1+. I doubt very much whether any human player would ever dream up _that_.
>>
>>Interestingly, the right move is played for the wrong reasons; Crafty, up until
>>then, plays 60..gxh3 with a score of -6.5. It then moves to 60..Rg1+ with a
>>score of -10 without ever realising that gxh3 should have a score of 0 ;)
>>
>>Alastair
>
>
>I'm not understanding the crafty comment above.  If Rg1 is -10, and gxh3 is -6,
>I can see why it would prefer Rg1 over gxh3, so that white has g1 as a way out.
>But why would it want to play a move that leads to a draw when it can get a -10,
>which is good for black???

The comment is that crafty does not see the draw
for gxh3 and prefers Rg1+ only because Rg1+
has a bigger advantage.

This is what was considered as the wrong reason
by the poster.

Uri



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