Author: David B Weller
Date: 11:03:59 07/02/04
Go up one level in this thread
Thanks Fabien.
Yes, the missing '-' was a mistake.
As it turns out, {-alpha-1, -alpha} are what I am using after the 1st move, and
if(val > alpha && val < beta) val = -pvs(-beta, -alpha) are the condition and
bounds of the re-search. I was actually hoping I had it all fouled up, so I
could 'IMPROVE' it significantly! :)
The 'heads-up' about storing mate scores with 'inflated' drafts was helpful. I
think that was messing some things up.
I have to think some more on this "mate-distance pruning".
>The "mate-distance pruning" I use is common, but I don't know a
>standard name for it. It is a completely different idea, that is
>actually independent of the transposition table. If at a given node
>you already have a "mate in 3" (= 5 plies) then only a "mate in 2" (=
>3 plies) or shorter could improve the current value. Therefore there
>is no need to look more than 3 plies ahead in any subtree. You might
>need to adjust depending on how you detect mates. Also most engines
>count mate distances "to the root", so implementation requires care.
thank you.
David
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