Author: Inmann Werner
Date: 12:32:02 10/05/99
Go up one level in this thread
On October 05, 1999 at 10:40:49, Robert Hyatt wrote: >On October 05, 1999 at 05:25:21, Bas Hamstra wrote: > >>What are good ways to cut down the number of evals? I saw Bob Hyatt post that he >>could easily double NPS when using "Lazy Eval". >> >>What is a correct way to do that? Is there more to it than the qsearch "delta" >>type of pruning? >> >> >>Regards, >>Bas Hamstra. > > >The idea is that in general, your eval _must_ return scores > alpha and >< beta, or they are not useful, correct? (please ignore this if you use >mtd(f) of course, as it is more complicated then). Suppose alpha=-.30 and >beta=+.30. When you get into your eval, if you can figure out that you >can't possible bring the score within that window, you can return the >appropriate bound quickly. IE if you come in and material is at -9.00 (You >have lost a queen somewhere in this path) then do you have an eval term that >can add +9.00 to the score to bring it inside the window? If not, you can >either return -9.00, or the more safe -.30, since the score is at least >that bad. > >You can use this at several points to bail out after you are sure you can't >get "in the box" with the score... why is giving back -0.30 a more safe way then returning the material_balance of -9.00, what I do now? Werner
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.