Author: Robert Hyatt
Date: 07:57:11 11/12/02
Go up one level in this thread
On November 12, 2002 at 03:31:58, Uri Blass wrote: >On November 12, 2002 at 02:06:21, Russell Reagan wrote: > >>On November 12, 2002 at 01:14:36, Uri Blass wrote: >> >>>If we evaluate every possible move by having a thread for every legal move >>>then we have an idea about the second best move. >> >>Starting a thread for every legal move serves no purpose. Either you are going >>to set them all to the same priority, and you will be searching (say) 35 moves >>for 1/35th of the time you are pondering. Basically you're doing a search with >>no pruning at the root. So you're doing exactly what the opponent is doing, only >>you will never see what he sees because you're not pruning away moves at the >>root. When the opponent moves, you will have only searched the "right" move >>1/35th of the time. So if the opponent takes 3 minutes to move, you only >>pondered on the "right" move for a little over 5 seconds. In a lot of positions >>there will be a lot more than 35 legal moves, and that number of seconds keeps >>dropping. Basically you just wasted that 3 minutes. >> >>If you set the threads with one to run at a higher priority than the others, the >>one that you set with a higher priority is going to dominate all of the other >>threads since it will always be searching, so you might as well have just >>pondered on that one move, because not a single one of the other threads are >>going to result in anything useful. >> >>Russell > >No > >If I see better score in one of the thread with low priority >or if I see fail low in the main thread then I can increase the priority >of one of the threads that was given originally low priority. > >Note that I do not use threads in movei but I guess that I can change the >priority of a thread during the search. > >Uri That is not going to work. First, running N searches at one time is going to kill alpha/beta performance. Second, all the threads will be competing for CPU time. The net result is that you are going to search four or five plies _less deeply_ which is going to be horrible.
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.