Starting with quiescence search

Discussion of chess software programming and technical issues.

Moderators: hgm, Rebel, chrisw

lauriet
Posts: 199
Joined: Sun Nov 03, 2013 9:32 am

Re: Starting with quiescence search

Post by lauriet »

I think i read Ed saying not to search loosing catures in QS.
Does this work just as well ?
You would still sort by mvv/lva but stop when that is negative.
Any comments ?
AlvaroBegue
Posts: 931
Joined: Tue Mar 09, 2010 3:46 pm
Location: New York
Full name: Álvaro Begué (RuyDos)

Re: Starting with quiescence search

Post by AlvaroBegue »

lauriet wrote:I think i read Ed saying not to search loosing catures in QS.
Does this work just as well ?
You would still sort by mvv/lva but stop when that is negative.
Any comments ?
No, you may not want to search captures with negative SEE, but more valuable pieces capturing less valuable pieces should be explored, if the victim is undefended.
User avatar
Luis Babboni
Posts: 464
Joined: Sat Feb 28, 2015 4:37 pm
Location: Argentina

Re: Starting with quiescence search

Post by Luis Babboni »

I tried QS with all captures till actual score is worst for engine than the score before start normal search.

I mean:

Without QS if maximum depth is n and in ply n a queen capture a pawn and there was no other capture in the pevious n-1 plies, the engine decides is a good move.
With my QS if at ply n a queen capture a pawn and there was no other capture in the pevious n-1 plies, it continues one more ply but if an opponent piece capturing the queen, it decides is not a good move to capture the pawn previously.

But I hope my conclusion that the performance was worst than without QS could be wrong!!! :roll:
Actual score with vs without is 18-7-0 in 300 40/4 games I started after a little adjust!! 8-)
Ras
Posts: 2487
Joined: Tue Aug 30, 2016 8:19 pm
Full name: Rasmus Althoff

Re: Starting with quiescence search

Post by Ras »

Well QS means computing additional stuff. Each QS is a little search tree of its own, with the eval being called at the leaves. If you compute more stuff, of course that takes more time.

But in the end, the raw plies search depth don't matter; what matters is finding good moves.