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Subject: Re: Cabablilities of a SEE

Author: Koundinya Veluri

Date: 10:24:57 10/05/01

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On October 04, 2001 at 07:03:14, Tim Foden wrote:

>Hi All,
>
>I decided that I would add a 2nd SEE to GLC to check whether GLC's SEE was
>working.  I actually ported GCP's Sjeng SEE (that was posted to the forum a
>while ago).
>
>Both SEE routines now agree in most curcumstances, but one's like the following
>have cropped up (where they disagree):
>
>[D]5rk1/1pp2R1p/p1pb4/6q1/3P1p2/2P4r/PP1BQ1P1/5RKN w - - 2 0
>
>This can be evaluated in 2 ways...
>
>(1) BxP (+1000) BxB (-3500) R1xB (+3500) QxR (-5500) RxQ (+10000) RxR (-5500)
>.........+1000.......-2500........+1000.......-4500........+5500...........0
>
>>>> value = 0
>
>(2) BxP (+1000) BxB (-3500) R7xB (+3500) RxR (-5500) RxR (+5500) QxR (-5500)
>.........+1000.......-2500........+1000.......-4500.......+1000.......-4500

My SEE doesn't differentiate between the two different methods. It actually
returns -200 (-2000 in your case) and when I traced it, I found this:

BxP (+100) BxB (-300)
.....+100.......-200

It stops there because it sees that capturing with a rook would lead to more
losses (it assumes the second case, where black captures with the rook first).
So the second case should really be terminated after BxP BxB, which would result
in a score around -200 (or -2000).

Koundinya

>
>>>> value = -2500
>
>So... on to the questions:
>
>a) Does anyone's SEE do anything intelligent in these cases?
>
>b) Is one of these right, and the other wrong?  If so, which one?
>
>c) Do we actually care, as long as the SEE works in the majority of cases?
>
>Cheers, Tim.



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