Author: Robert Hyatt
Date: 13:02:37 08/10/04
Go up one level in this thread
On August 10, 2004 at 15:32:57, Uri Blass wrote: >On August 10, 2004 at 12:52:28, Robert Hyatt wrote: > >>On August 10, 2004 at 10:59:29, Tord Romstad wrote: >> >>>On August 10, 2004 at 10:35:29, Anthony Cozzie wrote: >>> >>>>Plus, if you have only PST eval you should be getting 3-4M nps, so SEE probably >>>>slows you down a _lot_. >>> >>>Yet another proof of how bad my programming skills are. With PST eval and >>>nothing >>>else, I get about 800,000 nps (on a PIV 2.4 GHz). Adding SEE slowed me down to >>>around 750,000 nps. >>> >>>Tord >> >> >>SEE slowed me down by 10%. Move ordering improved to speed me up 10%. > Washed >>out to no advantage, _until_ I added the stuff about tossing out captures that >>can't bring the score back to within the alpha/beta window. > >I doubt if you can give one number for speed improvement thanks to better order >of moves. > >I think that the improvement can be bigger at longer time control. I don't believe the "percentage" will change, as I used long time controls for all my testing... I don't pay much attention to blitz except to spot gross problems... > > > > That made me about >>2x faster overall, which is a _big_ gain. > > >2xfaster overall only thanks to pruning? > >It seems to me too much advantage for SEE. I only report what I get. Hsu asked the question, I (and Stanback and others) ran the tests to see. > >Note that even without SEE you can prune in the qsearch captures that cannot >bring the score to alpha/beta window and if you are queen down relative to >alpha then it is clear that capture of a rook will not bring the score back to >alpha even without SEE so if the first version did not use that pruning you have >not fair comparison. That's a gross case. What about the case where the window is X, the current material is X-2.00, and now you need to know whether the capture will bring you back into the window. A good SEE score is _way_ better than MVV/LVA, as MVV/LVA would say that QxR is ok, where SEE would say -4 since the rook is defended. The test was simply "normal q-search" with pure losing captures thrown out with SEE vs normal q-search ordered by MVV/LVA." The current approach is a bit better than even that experiment of course. > >Uri
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