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Subject: Re: What do you do in your q-search

Author: Anthony Cozzie

Date: 09:07:09 11/23/02

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On November 23, 2002 at 04:36:01, Sune Fischer wrote:

>On November 23, 2002 at 00:57:57, Anthony Cozzie wrote:
>
>>The discussion on verified null move pruning has got me thinking about my
>>qsearch.  Right now zappa does simple-stupid qsearch: captures and recaptures,
>>and I'm thinking about adding some things.  If I have a better q-search it may
>>be possible to move to straight R=3, which would be faster than the current
>>R=2/3 (Heinz). So I am considering adding:
>>
>>1. Pawn Promotions. It would be very easy to add some sort of "generate white
>>pawn promotions".  Usually there would be none, but this could be determined
>>quickly by a bitboard and (for those of us smart enough to use bitboards . . . .
>>hehehe)
>
>If you trying to start WWIII, this is the way to do it :)
>And yeah, try adding promotions, try it all you never know if it really works
>for you.
>
>>2. Check evasion.  Right now if one of the captures puts the King in check in
>>qsearch, zappa just stops.
>
>Hmm, haven't tried that. I just continue and return stand pat score if no
>capture can get it out of check. Extending in qsearch is pretty delicate, tree
>is going to blow easily!
>
>>3. A Horizon zone.  For example, Search() would call horizon() which would call
>>QSearch().  In the horizon zone, Zappa would also search checks and killer
>>moves.
>
>Yeah, maybe - try it! Don't be affaid to experiment :)
>It might be good to have some sort of soft transition to qsearch, use a minimal
>of tactical extensions etc.
>
>>Secondly, what are people's opinions on SEE versus futility pruning in QSearch?
>>I was using SEE up until recently, when I did some experiments and decided
>>Qsearch was working better.  Of course, I may just have bugs in my SEE.
>
>"Qsearch was working better"?
>SEE shouldn't replace qsearch, it's not that accurate. I use it only for move
>ordering.

Slight mistake on my part here. I meant to say, "I was using SEE up until
recently, when I did some experiments and decided futility pruning was working
better"

anthony



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