Author: Omid David Tabibi
Date: 20:14:52 11/23/02
Go up one level in this thread
On November 23, 2002 at 22:25:02, Tony Werten wrote: >On November 23, 2002 at 22:14:27, Omid David Tabibi wrote: > >>On November 23, 2002 at 21:50:01, Tony Werten wrote: >> >>>On November 23, 2002 at 21:24:08, Omid David Tabibi wrote: >>> >>>>On November 23, 2002 at 21:09:36, Tony Werten wrote: >>>> >>>>>On November 23, 2002 at 20:52:01, Omid David Tabibi wrote: >>>>> >>>>>>On November 23, 2002 at 20:00:15, Tony Werten wrote: >>>>>> >>>>>>>On November 23, 2002 at 11:11:16, Christophe Theron wrote: >>>>>>> >>>>>>>>On November 23, 2002 at 09:22:37, jefkaan wrote: >>>>>>>> >>>>>>>>>oops, wasn't finished yet.. >>>>>>>>> >>>>>>>>>>are done by using the results of the positional eval >>>>>>>>>>to prune the q-search, >>>>>>>>>and there using only material eval >>>>>>>>> (haven't tried it out yet, and wouldn't >>>>>>>>>know how to do it, but it's only an idea, >>>>>>>>>you know.. to explore options of >>>>>>>>>more effective branch factor reducements >>>>>>>>>and efficient programming (besides >>>>>>>>>lousy solutions as inline assembler >>>>>>>>>and bitboards.. >>>>>>>>>:) >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>>Yes Chess Tiger does much more pruning than known (published) techniques. >>>>>>>> >>>>>>>>I think other top programs do it also. >>>>>>>> >>>>>>>>I still fail to see why the efficiency of an algorithm depends on what your >>>>>>>>QSearch does. >>>>>>>> >>>>>>>>If your pruning algorithm is good, it will increase the strength of the program >>>>>>>>regardless on how good your QSearch is. >>>>>>>> >>>>>>>>If your QSearch is smart, then it will increase the strength even more. >>>>>>>> >>>>>>>>I don't like the idea that some algorithms that have almost nothing to do with >>>>>>>>each other would have such an influence on each other. It is indeed possible and >>>>>>>>it probably happens all the time, but it's hard to work with such hypothesis in >>>>>>>>mind. >>>>>>>> >>>>>>>>I think it's better to first assume that the kind of QSearch you do will not >>>>>>>>interfere with the quality of the pruning algorithm used before the QSearch. >>>>>>>> >>>>>>>>If your QSearch sucks, it's not because you are doing a lot of pruning in the >>>>>>>>"full width" part of the search. It's because it sucks. >>>>>>> >>>>>>>The paper does prove that the more your (q)search sucks, the better your pruning >>>>>>>algoritm seems. But that's not really news. >>>>>>> >>>>>> >>>>>>Does it prove that?! No, it's just my impression based on the data gathered so >>>>>>far. Maybe a reduction of 2 (instead of 1) in case of fail-high report, will >>>>>>work better in programs with heavy extensions and quiescence. >>>>> >>>>>A reduction of 20% seems to be working best in XiniX ( heavy qsearch). >>>> >>>>What do you mean by 20%? (you used a reduction of 1 or 2 in case of fail-high >>>>report?) >>> >>>In case of a fail high I reduce the depth with 20%. ( doesn't work in your silly >>>program :) >>> >> >>Anyway, no matter what the reduction is, you are using verified null-move >>pruning, which is good :-) In my paper I just gave a new null-move pruning >>framework; feel free to play with the values that best fit your program. > >It's a no brainer to implement. If it's not bad then it's worth investigating. > >> >>Even better values do exist. I've been working on them for some time and will >>publish them in near future. > >If I might give an advice. For first reviews, send them it to some active >chessprogrammers, and not to academic has beens. It will save you a lot of >typework. ( you have been quite active on this forum lately ) > I will. However, after posting a new method, several days of "heavy presence" will always be needed to clear things up and answer the questions... >BTW last time we mailed I concluded your last name was David, were does the >Tabibi come from ? > My full name has always been Omid David Tabibi. But I usually use just David as my last name in informal occasions. After ICGA put my name as "O.D. Tabibi" on their cover, I thought it would be a good idea to use my full name here to avoid confusion. >Tony > >> >> >>>In XiniX I have partial extensions (PLY is 32). >>>The addition to your idea is to give big reductions when there is still a lot of >>>searchdepth remaining. So fe when there is 12 ply left I give more reduction >>>than when there's 6 ply left (with a minimum of 1 ply ) That's 6*0,2 is 1,2 ply >>>more. For XiniX that seems to make the difference between a good and a bad new >>>idea. >>> >>>Tony >>> >>>> >>>> >>>>>I'm >>>>>interessed in your idea. It's commented out in my program now, but not deleted. >>>>>I still have to play with it some more. >>>>> >>>>>Despite of the negative comments you had, I don't think it's a bad idea. I'm >>>>>just not convinced yet it's a good one. >>>>> >>>> >>>>It took me several months of experiments to get convinced. After a little more >>>>tuning and playing with different reduction values (1 or 2), I believe you will >>>>be convinced too ;-) >>>> >>>> >>>>>Tony >>>>> >>>>> >>>>> >>>>>> >>>>>> >>>>>>>Tony >>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Christophe
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