Author: Mikael Bäckman
Date: 04:35:19 03/17/04
Go up one level in this thread
On March 17, 2004 at 06:08:02, Sune Fischer wrote: >On March 17, 2004 at 05:50:57, Mikael Bäckman wrote: > >>On March 17, 2004 at 05:26:30, Sune Fischer wrote: >> >>>On March 17, 2004 at 05:17:43, Mikael Bäckman wrote: >>> >>>>>Just a single test position to depth 15: >>>> >>>> >>>>Testing on a single position is wrong. >>>>If you take 20 positions and repeat the test, are the results still the same? >>>> >>>>/Mikael >>> >>>True. >>> >>>I have tested on other positions back when I started using this, but as you can >>>see it takes a long time for each position so I just tried a single one this >>>time. >>>If the search is deep enough I always get the same pattern with the local >>>overtaking the global. >>> >>>It would be interesting to see if Crafty and other engines exibit the same >>>behavior, I would expect so but one never knows :) >>> >>>-S. >> >>I can run some tests when I get home, but I would need to know exactly how you >>'localize' the HH. Divide with X every N nodes? > >Yes, pretty much. >I scale it down by a factor 8 when the entries hit a certain limit, ie. > >if (hist[index]>X) > for (i...) > hist[i]=hist_seed[i]+(hist[i]>>3); > >>My history tables in chepla look like history[stm][piece][to], it will be >>interesting to compare the numbers. > >That should be possible, as I use the exact same type of table. > >>One thing to check before running these tests. >>I had a bug a while ago where my History tables would overtake the good captures >>in movesorting: I add a base value of B for all good and equal captures. In some >>deep searches (mostly endgames searches) history values would become greater >>than B... > >History scores can get quite big and tough to beat :) > >One solution could be to search all the captures before you even assign history >scores to the non-captures. I don't have such advanced movegenerators yet. :) I use 0x88 and don't keep track of threatened pieces. I have to loop to find pieces capturable by sliders, so I generate all moves at once. /Mikael > >-S. >>/Mikael
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.