Author: Tony Werten
Date: 23:44:52 11/21/02
Go up one level in this thread
On November 21, 2002 at 17:01:11, Omid David Tabibi wrote: >On November 21, 2002 at 16:55:04, Tony Werten wrote: > >>On November 21, 2002 at 16:19:17, Omid David Tabibi wrote: >> >>>On November 21, 2002 at 16:05:45, Tony Werten wrote: >>> >>>>On November 21, 2002 at 13:52:33, Omid David Tabibi wrote: >>>> >>>>>On November 21, 2002 at 13:05:28, Uri Blass wrote: >>>>> >>>>>>On November 21, 2002 at 09:16:09, Omid David Tabibi wrote: >>>>>> >>>>>>>On November 21, 2002 at 08:34:36, Uri Blass wrote: >>>>>>> >>>>>>>>1)I do not find in the pseudo code in figure 3 undo null move. >>>>>>>> >>>>>>>>I assume that it should be before if value>=beta and after value=-search(...) >>>>>>>>Am I right? >>>>>>>> >>>>>>> >>>>>>>That is why it is called *pseudo*-code :-) >>>>>>>You have to fill in the obvious parts by yourself... >>>>>>> >>>>>>> >>>>>>>>2)What is the value of the research for tactical strength? >>>>>>>>Should it help significantly relative to searching to reduced depth when >>>>>>>>value>=beta without research (even when we get value that is less than beta). >>>>>>>> >>>>>>> >>>>>>>I didn't understand the question. Dp you mean doing a shallow search even when >>>>>>>we don't have a fail-high report?! >>>>>> >>>>>>I meant to ask what is the tactical value of the research(You suggested people >>>>>>to start with doing it without the research first and only after it works to do >>>>>>it with the research) >>>>>> >>>>> >>>>>The re-search is needed only in zugzwang positions. Such zugzwang positions >>>>>occur very rarely in midgames; so you can forgo the zugzwang detection re-search >>>>>and still benefit all the improved tactical performance. >>>> >>>>I was quite surprised to see them from the starting position at a rate of 5 per >>>>second. Not impressive, XiniX searches 400 Kn/s there, but still surprising. >>>> >>> >>>The rate of what, was 5 per second? >> >>"Zugzwang positions" or rather, positions where nullmove would have given a >>cutoff but that after reducing depth and searching gave a score < beta. >> > >You mean you got an average of 5 zugzwang indications per second in middle >game?!!! Then your program has instabilities which cause a huge number of >needless re-searches due to false zugzwang alarm. Turn off your zugzwang >detection at once! I'm quite interested in finding out what is happening so I'll leave it in for a while. I think it has something to do with tempo. XiniX doesn't use futility pruning so I'm quite curious to know if programs that do, have a bigger false zugzwang count. Tony > > >>Tony >> >>> >>> >>>>Tony >>>> >>>>> >>>>> >>>>>>Uri
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