Author: Carlos del Cacho
Date: 13:34:53 01/27/01
Go up one level in this thread
On January 27, 2001 at 14:30:18, Severi Salminen wrote: >Hi! > >I made a few test games between a version of my engine using SEE and another >using just MVV sorting. I played only a few (24) games and time control was >5min/G and in 8 games 1min/G. The result was 12-12! Is this possible, normal, or >do I have a bug? I would have guessed that the SEE version had beat the hell out >of the other but that never happened. It seems that SEE slows things down a lot >and the net result seems to be that it searches equally deep compared to the >other version. Has anyone here measured the true benefit of using SEE? Could you >show me positions in which SEE makes a big difference or could you run self-test >games between two versions of your program? Are there positions where SEE hurts >searching? I really like to know if SEE is worth it? I have a relatively slow >computer (300Mhz Celeron, Crafty running at 80KNPS) so could time control and >overall speed have influence on this? > >Any comments are welcome! > >Severi Just a quick test. Two runs on WAC 5 sec/problem: - SEE pruning in Quiescent Search: 270 - without it: 246 So it is definitely a win for my program (Pepito). The only difference between these builds was commenting out these lines: val = SEE(pos_stack->jug); if (val < 0) continue; val += MARGEN_QUIES + pos_eval; if (val <= alpha) continue; But you should note that I try not to call the SEE function whenever possible. If I can get a cut with pos_eval + mat_gain I give up this capture. Another question is if SEE is profitable in normal search. I also it there but kicking it out would be a bit more difficult so I haven't tried yet :-). At the same time captures are generated I assign them their MVV/LVA scores. Then I try captures with positive scores and when this gets below zero I call SEE for remaining moves. Losing ones are searched after all non captures. I'm not really sure about the gains here so I'll give it a try... Greets, Carlos
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.