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futility pruining, razoring question
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Martin Sedlak



Joined: 26 Nov 2010
Posts: 701
PostPost subject: Re: futility pruining, razoring question    Posted: Mon Apr 09, 2012 9:04 pm Reply to topic Reply with quote
elcabesa wrote:

talking about Razoring
Code:
if(!isCheck && beta ==alpha+1 && depth<=3 && abs(beta) < CHECKMATESCORE - 1000){

   int score=board.eval();

        if ( score + razoringMargin(depth) < alpha )
        {

            int res = qsearch( ply, alpha-razoringMargin(depth), beta - razoringMargin(depth) );
           if (res - razoringMargin(depth) <= alpha)   
             return score;
        }
    }
}


what still I havent' understood is how big could be razorMargin.


I guess it should be:

Code:
if(!isCheck && beta ==alpha+1 && depth<=3 && abs(beta) < CHECKMATESCORE - 1000){

   int score=board.eval();

        if ( score + razoringMargin(depth) < alpha )
        {

            int res = qsearch( ply, alpha-razoringMargin(depth), beta - razoringMargin(depth) );
           if (res + razorMargin(depth) <= alpha )   
             return score; // or res or alpha
        }
    }
}


as for razormargin, i guess you are looking for values between 1 to 4 pawns. Best is to test which values are optimal for your engine.
I tried to measure razoring success for static margin of a minor piece in my engine and got something like 99.5% success rate, which means in 0.5% it razored cut nodes instead of all nodes; but it will depend on a type of position. In balanced positions it will be much closer to 100%. My guess is that you can try lower margin when you are closer to the leafs.
I hope I didn't write a BS Smile

Martin
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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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