Author: Uri Blass
Date: 20:30:22 04/01/04
Go up one level in this thread
On April 01, 2004 at 22:30:27, Eugene Nalimov wrote: >On April 01, 2004 at 21:38:22, Marc Bourzutschky wrote: > >>On April 01, 2004 at 21:30:23, Eugene Nalimov wrote: >> >>>On April 01, 2004 at 21:15:05, Marc Bourzutschky wrote: >>> >>>>On April 01, 2004 at 20:36:32, Eugene Nalimov wrote: >>>> >>>>>On April 01, 2004 at 20:03:20, Marc Bourzutschky wrote: >>>>> >>>>>>On April 01, 2004 at 17:59:38, Eugene Nalimov wrote: >>>>>> >>>>>>>On April 01, 2004 at 15:16:34, Marc Bourzutschky wrote: >>>>>>> >>>>>>>>The Chessmaster format is indeed better >>>>>>> >>>>>>>What does it mean "better"? :-) >>>>>>> >>>>>>>It stores less information, thus compresses better. >>>>>>> >>>>>> >>>>>>No, it stores the same information, just in two different files. Those files >>>>>>together are still somewhat smaller than the Kadatch compressed ones... >>>>> >>>>>AFAIK it doesn't stores non-wins for side to move. Is it so? That alone should >>>>>result in the better compression. >>>>> >>>> >>>>It stores complete information, just distributed differently. For example, the >>>>equivalent of the Nalimov krpkr in FEG is the set of krpkr and krkrp. Each >>>>stores only wins for the side to move, but between the two you get the exact >>>>same win/loss/draw information. krpkr and krkrp in FEG format togther occupy a >>>>little under 127Mb, while the krpkr.nb?.emd files take 150Mb. The complete >>>>5-man set in FEG is about 5.6Gb. >>> >>>Ok, let's assume that position in krpkr is loss for white to move. Where in FEG >>>that information is stored? Not in krpkr, because it is not win for side to >>>move. Not in krkrp because other side is to move. >>> >>>What I don't understand? >>> >> >>Yes, the information is stored in krkrp "flipped" with black to move. In the >>Nalimov format you don't need krkrp because krpkr stores both wins and losses, >>while the FEG format does not need to store losses because they are in krkrp. >>In fact, I used the 1-1 correspondence between Nalimov and FEG to trace an e.p. >>bug in an earlier version of FEG :-) > >I see. So in FEG your have krpkr wtm, krpkr btm, krkrp wtm, and krkrp btm. Than >yes, you can figure value without the search, at a cost of (probable) extra TB >probe. Extra probe is unavoidable when the score is a draw. practically it is avoidable because you can assume that the stronger side does not lose unless the remaining depth is big because cases when KRP is losing against KR are rare and cases when KBN is losing against KN are even more rare. Uri
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