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futility pruining, razoring question
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Marco Costalba



Joined: 14 Jun 2008
Posts: 2090
PostPost subject: Re: futility pruining, razoring question    Posted: Fri Apr 06, 2012 5:45 am Reply to topic Reply with quote
Well, clearly razoring has no sense in PV (even theoretically) . Near leaves of PV you expect value to be above alpha, and in case you find a fail low at next iteration you really don't want to find it through razoring. But I suspect Bob was referring to something else than all of us: normally I use chessprogramming as a name reference, but I think he is using other references and probably with 'razoring' he is referring to forward pruning or something like that.

Regarding Luca's code I find this:

Code:

const int score = qsearch(B, alpha, beta, 0, ply+1, is_pv, si+1);


a really optimistic assumption, normally you want to verify with a reduced margin, not with alpha. If this was also in your original code, perhaps could be a reason why it didn't work for you and so you switched to a kind of reduction instead of pruning.
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Subject Author Date/Time
futility pruining, razoring question Marco Belli Wed Apr 04, 2012 6:21 pm
      Re: futility pruining, razoring question Robert Hyatt Thu Apr 05, 2012 7:07 pm
            Re: futility pruining, razoring question Karlo Bala Jr. Thu Apr 05, 2012 7:59 pm
            Re: futility pruining, razoring question Vincent Diepeveen Thu Apr 05, 2012 11:47 pm
      Re: futility pruining, razoring question Lucas Braesch Fri Apr 06, 2012 3:34 am
      Re: futility pruining, razoring question Martin Sedlak Fri Apr 06, 2012 3:35 am
            Re: futility pruining, razoring question Martin Sedlak Fri Apr 06, 2012 4:10 am
      Re: futility pruining, razoring question Martin Sedlak Fri Apr 06, 2012 5:15 am
            Re: futility pruining, razoring question Marco Costalba Fri Apr 06, 2012 5:45 am
                  Re: futility pruining, razoring question Lucas Braesch Fri Apr 06, 2012 7:22 am
                        Re: futility pruining, razoring question Martin Sedlak Fri Apr 06, 2012 7:30 am
                              Re: futility pruining, razoring question Lucas Braesch Fri Apr 06, 2012 8:36 am
                                    Re: futility pruining, razoring question Marco Costalba Fri Apr 06, 2012 11:42 am
                                          Re: futility pruining, razoring question Lucas Braesch Fri Apr 06, 2012 1:21 pm
                                          Re: futility pruining, razoring question Ricardo Barreira Fri Apr 06, 2012 3:00 pm
                              Re: futility pruining, razoring question Vincent Diepeveen Fri Apr 06, 2012 5:21 pm
                                    Re: futility pruining, razoring question Lucas Braesch Sat Apr 07, 2012 1:59 am
                                          Re: futility pruining, razoring question Vincent Diepeveen Sat Apr 07, 2012 8:22 am
                                                Re: futility pruining, razoring question Marco Costalba Sat Apr 07, 2012 9:52 am
                                                Re: futility pruining, razoring question Vincent Diepeveen Sat Apr 07, 2012 1:53 pm
                                                      Re: futility pruining, razoring question Ed Schroder Sat Apr 07, 2012 3:46 pm
                                                            Re: futility pruining, razoring question Vincent Diepeveen Sat Apr 07, 2012 4:07 pm
                                                      Re: futility pruining, razoring question Lucas Braesch Sun Apr 08, 2012 3:08 am
                                                            Re: futility pruining, razoring question Vincent Diepeveen Sun Apr 08, 2012 10:12 am
                                                                  Re: futility pruining, razoring question Matthew R. Brades Sun Apr 08, 2012 11:18 am
                                                                        Re: futility pruining, razoring question Marco Belli Mon Apr 09, 2012 7:42 pm
                                                                              Re: futility pruining, razoring question Marco Belli Mon Apr 09, 2012 8:23 pm
                                                                              Re: futility pruining, razoring question Martin Sedlak Mon Apr 09, 2012 9:04 pm
                                                                                    Re: futility pruining, razoring question Marco Belli Mon Apr 09, 2012 9:24 pm
                                                                                          Re: futility pruining, razoring question Marco Belli Tue Apr 10, 2012 10:52 am
                                                                                          Re: futility pruining, razoring question Martin Sedlak Tue Apr 10, 2012 11:58 am
                        Re: futility pruining, razoring question John Merlino Sat Apr 07, 2012 5:10 pm
                              Re: futility pruining, razoring question Vincent Diepeveen Sat Apr 07, 2012 5:41 pm
                                    Re: futility pruining, razoring question John Merlino Sat Apr 07, 2012 5:54 pm
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