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optimal aspiration window for stockfish question
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Lucas Braesch



Joined: 31 May 2010
Posts: 2491

PostPost subject: Re: optimal aspiration window for stockfish question    Posted: Sun Mar 18, 2012 5:55 am Reply to topic Reply with quote

bob wrote:
mcostalba wrote:
bob wrote:
I'm beginning to think that the +/- infinity idea is just as good as aspiration search. Most likely because we all use PVS (null-window, not null-move) anyway. I did not go all the way to infinity in my test results I posted here, but I will try it to see if it makes any difference. (I suspect there will be no change at all).


A little detail: aspiration window should not start from iteration 1, in Stockfish it starts from iteration 5 and before we use +-inf.


Why would it matter? Those iterations take microseconds to complete. Doesn't matter how many re-searches you do down there...

I confirm what Robery is saying. I've done some testing in DoubleCheck with that, and found the minimum depth condition to be useless. However, if it doesn't help, it cannot hurt, and it reduces the nodecount on a "./DC bench" (I haven't tried with "./stockfish bench" but I'm almost certain it's the same). But I kept the condition anyway, as it may have an impact at stupidly fast games (sometimes I test without time control and just a node limit of 50k nodes for example).

But there is another condition in StockFish which might make more sense. If the score is a mate score (or a winning endgame by EG knowledge which returnsd high scores) then SF doesn't do aspiration. I haven't done any serious measurement on that, but it makes sense. Although I expect no elo improvement from it, it should make SF waste less time in researches when it's finding a mate, which is nice for analysis.
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Subject Author Date/Time
optimal aspiration window for stockfish question Uri Blass Mon Mar 12, 2012 11:14 am
      Re: optimal aspiration window for stockfish question Ed Schroder Mon Mar 12, 2012 12:55 pm
            Re: optimal aspiration window for stockfish question Marco Costalba Mon Mar 12, 2012 6:47 pm
                  Re: optimal aspiration window for stockfish question Don Dailey Mon Mar 12, 2012 9:41 pm
                        Re: optimal aspiration window for stockfish question Robert Hyatt Wed Mar 14, 2012 10:18 pm
                              Re: optimal aspiration window for stockfish question Marco Costalba Thu Mar 15, 2012 6:15 am
                                    Re: optimal aspiration window for stockfish question Robert Hyatt Thu Mar 15, 2012 2:06 pm
                                          Re: optimal aspiration window for stockfish question Robert Hyatt Thu Mar 15, 2012 5:30 pm
                                                Re: optimal aspiration window for stockfish question Robert Hyatt Thu Mar 15, 2012 8:11 pm
                                                      Re: optimal aspiration window for stockfish question (update Robert Hyatt Thu Mar 15, 2012 9:55 pm
                                                            Re: optimal aspiration window for stockfish question (update Miguel A. Ballicora Thu Mar 15, 2012 10:23 pm
                                                                  Re: optimal aspiration window for stockfish question (update Robert Hyatt Fri Mar 16, 2012 3:29 am
                                                                        Re: test results Robert Hyatt Fri Mar 16, 2012 3:41 am
                                                                              Re: test results Rémi Coulom Fri Mar 16, 2012 8:38 am
                                                                                    Re: test results Robert Hyatt Fri Mar 16, 2012 5:20 pm
                                                                              Re: test results Karlo Bala Jr. Fri Mar 16, 2012 11:30 am
                                                                                    Re: test results Robert Hyatt Fri Mar 16, 2012 5:26 pm
                                                                                          Re: test results Ed Schroder Fri Mar 16, 2012 6:31 pm
                                                                                          Re: test results Robert Hyatt Fri Mar 16, 2012 7:16 pm
                                          Re: optimal aspiration window for stockfish question Vincent Diepeveen Sat Mar 17, 2012 1:44 pm
                                                Re: optimal aspiration window for stockfish question Robert Hyatt Sat Mar 17, 2012 4:11 pm
                                                      Re: optimal aspiration window for stockfish question Marco Costalba Sat Mar 17, 2012 5:28 pm
                                                            Re: optimal aspiration window for stockfish question Robert Hyatt Sun Mar 18, 2012 3:28 am
                                                                  Re: optimal aspiration window for stockfish question Lucas Braesch Sun Mar 18, 2012 5:55 am
                                                                        Re: optimal aspiration window for stockfish question Joona Kiiski Sun Mar 18, 2012 9:02 am
                  Re: optimal aspiration window for stockfish question Robert Houdart Mon Mar 12, 2012 10:44 pm
                        Re: optimal aspiration window for stockfish question Robert Houdart Tue Mar 13, 2012 9:18 am
                              Re: optimal aspiration window for stockfish question Uri Blass Tue Mar 13, 2012 10:12 am
                                    Re: optimal aspiration window for stockfish question Karlo Bala Jr. Wed Mar 14, 2012 7:46 pm
                                          Re: optimal aspiration window for stockfish question Robert Hyatt Thu Mar 15, 2012 9:49 pm
                  Re: optimal aspiration window for stockfish question Lucas Braesch Wed Mar 14, 2012 4:10 pm
                        Re: optimal aspiration window for stockfish question Eelco de Groot Wed Mar 14, 2012 7:30 pm
                              Re: optimal aspiration window for stockfish question Lucas Braesch Thu Mar 15, 2012 2:03 am
                                    Re: optimal aspiration window for stockfish question Marco Costalba Thu Mar 15, 2012 6:13 am
      Re: optimal aspiration window for stockfish question Eelco de Groot Tue Mar 13, 2012 10:20 am
            Re: optimal aspiration window for stockfish question Uri Blass Tue Mar 13, 2012 12:57 pm
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