Author: Vasik Rajlich
Date: 06:52:05 08/17/05
Go up one level in this thread
On August 17, 2005 at 05:36:21, Uri Blass wrote: >On August 17, 2005 at 05:07:05, Vasik Rajlich wrote: > >>On August 16, 2005 at 17:26:28, Uri Blass wrote: >> >>>On August 16, 2005 at 17:16:33, Paolo Casaschi wrote: >>> >>>>>I know that usually when program improve they improve in all time controls. >>>>>I do not know of evaluation changes or search changes that make programs weaker >>>>>at blitz but stronger at long time control. >>>>> >>>>>In thoery it can happen but I need to see a proof for it and I believe that >>>>>fabien mainly test in blitz time control(he can correct me if I am wrong) >>>>>because usually productive changes in blitz of adding knowledge to the >>>>>evaluation are also productive at long time control. >>>> >>>>Do you have any proof or evidence that there is some correlation between blitz >>>>strenght and slower speed strenght? >>>>If you dont, then we can only compare assumptions and I tend to agree with Bob >>>>Hyatt since the same non-correlation is evident with humans and because common >>>>sense... >>>> >>>>--Paolo >>> >>>Of course there is correlation. >>> >>>Look at every rating list at long time control and you can see Shredder,Fruit >>>Fritz,Junior,Hiarcs at the top of the list. >>> >>>Now look at rating list at blitz. >>>What do you see? >>> >>>Surprise for you >>>Again the same programs. >>> >>>You do not believe it? >>>Here are 2 rating lists one for blitz and another one for longer time control. >>> >>> >>>http://www.husvankempen.de/nunn/rangliste.html >>>http://www.miko42.de/turniere/blitzturniere/blitzrangliste.html >>> >>> >>>Uri >> >>1 minute/move on one processor is a sort of blitz, compared to 2 or 3 >>minutes/move on 8 processors. >> >>It makes sense to me that highly selective search works better at shorter time >>controls. It also seems that we have some data which starts to confirm this. >> >>For example, in this WCC, you've got three programs (Crafty, Zappa and Fruit) >>who use (apparently) a plain search, and two who are (apparently) much more >>selective (Shredder and Junior). Look who is overperforming and underperforming, >>compared to rating lists from faster time controls. >> >>Another issue is the books. Shredder for example has a "big" book, which is >>maybe good for blitz & SSDF but awful for this sort of time control. >> >>It seems that some of the work of the professionals is going to be wasted as >>hardware moves forward. >> >>Vas > >I do not know why do you think that fruit does not use selective search. >I think that history based pruning is type of selection. > >I also do not know what type of search use programs without source code and I >have no idea why do you think that zappa use plain search when Junior and >Shredder use selective search. > >You may suspect that it is the case for shredder because it searches deeper and >sometimes has problems to solve relatively simple positions but I do not know >what is the basis for this opinion about Junior when Junior does not have plies >in the same meaning of other programs and the fact that Junior is fast searcher >means that it does not waste much time in selecting moves. > >The problem of Junior in the only game that it lost(against Crafty) was not >selective search but bad evaluation > >Uri Fruit is relatively non-selective. Basically it does null move and a very safe form of fail-low reducing backed up by history table. Minimal extensions -recaptures only along PV, no passed pawns, nothing fractional. No futility pruning. Even no transposition table pruning along PV. As for the non-open source engines, I think it's pretty certain based on various author comments. Amir has discussed Junior many times in the CCC archives - they have some sort of a scheme of costing 2 plies for unpromising moves, and tons of extensions. Re. Junior-Crafty, yeah I don't know what Junior saw there - probably the eval was too optimistic. Even in games like this, though, there are search effects. Why don't you take the position after Nxf7 and play Junior-Crafty on one processor in a blitz game. I'll bet on Junior. Vas
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