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futility pruining, razoring question
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Vincent Diepeveen



Joined: 09 Mar 2006
Posts: 1738
Location: The Netherlands
PostPost subject: Re: futility pruining, razoring question    Posted: Sat Apr 07, 2012 1:53 pm Reply to topic Reply with quote
Indeed small sign problem hereby corrected and we see
directly why it is important to keep things simple:

Code to razor at TOP of the position:

Code:

if( depthleft <= 3 && eval <= alpha - QueenValue - 1 pawn ) return eval;


beta razoring:
Code:

Code:

if( depthleft <= 3 && eval >= beta + 1.5 pawn ) return eval;


Oh by the way the 10 pawn window for alpha was used by Ed,
i'd be very careful razoring on alpha indeed as you correctly warn,
yet i would start testing the above and do without qsearch first.

Only after that test WITH qsearch. It's trivial to test all combinations there though i'd say...

In Diep razoring doesn't work at all.

Note that positional COMPENSATION (not to confuse with the grand total) in total can easily add up to 50 pawns in Diep. By just grabbing some of the big bonuses/penalties,
and throw those in a 'quickeval' in Diep i can get in 99% of the cases to the full evaluation within 3 pawns actually.

Yet it's that 1% that's outside that is so important and decides how strong Diep actually plays Smile

Nevertheless, if you razor, your hashtables will be so total overloaded and give cutoffs everywhere also to refute moves that otherwise would make it to the mainline, especially if you search in parallel, that you better can razor in a drastic manner IMHO if you do it at all.
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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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