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Subject: Re: SEE and pin detection

Author: Vasik Rajlich

Date: 06:38:25 08/31/04

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On August 31, 2004 at 08:15:42, Kolss wrote:

>On August 31, 2004 at 06:52:10, Vasik Rajlich wrote:
>
>>On August 30, 2004 at 19:44:50, Eugene Nalimov wrote:
>>
>>>On August 30, 2004 at 14:03:49, Dan Honeycutt wrote:
>>>
>>>>In spite of Dr. Hyatt's admonishment that this was a loser in Crafty, I'm bent
>>>>on trying it.  Since I do legal move generation I can do the pins for half price
>>>>- I either have or can use the pin data for one side in conjunction with
>>>>generating moves.  I just finished the routine.  My NPS dropped by just over 4%
>>>>on bench test psitions.  I've just started testing an hope to have some
>>>>indication if pin detection is a win, lose or draw in a few days.
>>>>
>>>>One aside - the pin detection is not always more accurate (or mine isn't).  In
>>>>the following position for the move Nxg5 the no-pin SEE correctly returns +1
>>>>where the pin-detection SEE comes back with -2.
>>>>
>>>>[D] 7k/4q3/8/6p1/4N3/5N2/8/4K3 w - -
>>>
>>>
>>>White is lost in 24 :-)
>>>
>>>Thanks,
>>>Eugene
>>
>>Really? This ending is only lost in exceptional cases - and it's certainly not
>>obvious that this is one of them.
>>
>>Vas
>
>Hi Vas,
>
>Are you sure? It seems to me that this ending (Q vs. NN) is generally won for
>the queen. Maybe someone with the TB could check...
>
>Best regards - Munjong.

Yes - but there exist some complicated zugzwang positions, even in the middle of
the board. I guess here black can already force one of them.

Vas



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