Author: Dann Corbit
Date: 11:18:24 03/05/04
Go up one level in this thread
On March 05, 2004 at 09:12:39, Mathieu Pagé wrote: >On March 04, 2004 at 15:25:53, Dann Corbit wrote: > >>On March 04, 2004 at 15:16:43, Mathieu Pagé wrote: >> >>>Hi, >>> >>>I've just change my minimax algorithm for an AB one. (Yes I know i should have >>>done this long long time ago, but i did want to keep it simple until it could >>>play a complete game and understand _all_ the chess rules). >>> >>>As expected my engines can search deeper (3-4 more plys) than the old version in >>>the same time, but the NPS drop dramatically, going from 3.6M nodes/s to a >>>little bit over 2M nodes/s. It's about 44 % decrease. >>> >>>I think it is normal that the nps of Minimax was greater then AB's one because >>>in AB lot of move are generated, but not searched (so they are not add to the >>>number of nodes) >>> >>>but i think that going from 3.6M to 2M is a big difference. >>> >>>Is this behavior normal or did I put an unusual overhead in my algorithm (For >>>now, i have carefully revised my code and can not see what it is) ? >>> >>>TIA :) >>> >>>Mathieu Pagé >> >>How do you count nodes? > >Each call to AB, I count it as a node. (I have no quiescence or other fancy >things) Then I would expect what you are seeing. >>Does your perft calculation give a different rate now? > >No, my perft is as fast as it was (over 4 millions nodes per seconds) I would not worry about it then. >>I suspect the difference is that you spend more time in the search and less time >>in the move generator. But that is only a guess. > >I guess you mean more time in the move generation less in the search. did you ? No. If you spent more time in the move generator, you would be closer to the 4 million NPS. You spend more time in the search and call the move generator less often. That is generally a good thing. You will see the same thing when you strengthen your evaluation, because it will spend more time in eval and less in move generation. For an experiment, strap on an evaluation that does nothing but count wood. Probably, you will see something very high in NPS like one million and stupendous depth. But it will play like crap. >Note that i still have no ordering except a primitive LVA (without MVV ??) move >ordering is the next step on my TODO Hash next. The most important thing for move ordering is hashing, by far.
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.