Author: Omid David Tabibi
Date: 04:01:46 11/24/02
Go up one level in this thread
On November 23, 2002 at 23:33:39, Tony Werten wrote: >On November 23, 2002 at 23:14:52, Omid David Tabibi wrote: > >>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... > >Yes, that's good. > >I just think that sending your algoritm to Robert (I think we were using this in >74 ), Gian Carlo ( Can't work, just implemented it in 3 seconds ) and me ( >didn't crash my program, must be a good idea ) would have given you some "real" >input. > Yes, I agree. At least I would have changed my too optimistic comment "it can be implemented by merely adding a few lines of code"! It is a few lines of pseudo-code, but practically needs some more tuning to find the best reduction values... >Tony > >> >> >>>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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