Author: Steve Coladonato
Date: 08:20:19 11/22/04
Go up one level in this thread
On November 22, 2004 at 09:16:58, Laurens Winkelhagen wrote: >On November 22, 2004 at 07:53:27, Steve Coladonato wrote: > >>On November 22, 2004 at 05:49:05, Laurens Winkelhagen wrote: >> >>>On November 21, 2004 at 19:49:42, Steve Coladonato wrote: >>> >>>>On November 19, 2004 at 15:45:51, GuyHaworth wrote: >>>> >>>>> >>>>>Confirmed: Marc has done KRPKBP and Eugene has done 19+ 3-3p EGTs but not this >>>>>one. >>>>> >>>>>1-0 maxDTM = 166 wtm and 153 btm: 0-1 maxDTM = 103 wtm and 104 btm. >>>>> >>>>>g >>>>Guy, >>>> >>>>I'm not familiar with tablebases and I don't understand your score. I am >>>>reading it this way: maxDTM = Max depth to mate >>>> wtm = white to move >>>> btm = black to move >>>>What I don't understand is the 1-0 and 0-1 score. Could you explain it for me? >>>> >>>>Thanks. >>>> >>>>Steve >>>My guess: >>> >>>Because there is a difference between the white and black side, it makes a >>>difference which side mates. The above score tells us that the biggest maxDTM is >>>when the white (KRP) is to move and to win. >>> wtw btw >>>wtm 166 103 >>>btm 153 104 >>> >>>It seems logical that if black (KBP) is to win, then the mate should be shorter, >>>because one may not give white a chance to take the pawn with the rook. >>>Obviously this is easier when the pawn is closer to promotion. >>> >>>One puzzling thing left is that it makes a big difference for white to mate if >>>black is to move or white is. One would expect only a difference of 1, not of >>>13. It probably has something to do with going over into a different tablebase? >>> >>>Regards, Laurens >> >>Laurens, >> >>I thought the purpose of the tablebases was to provide "best" move evaluation of >>a position. In which case, only one side [either white or black but not either] >>would win or it is a draw. I suppose the starting position could enter into >>which side will win and perhaps that is why the above shows statistics for >>either side winning. >> >>Steve > >Hi Steve, > >I'm not sure if I understand you correctly, so I don't know if this reply will >make sense to you, but: >tablebases only tell only one side of the story: there is a KRPKBP tablebase but >there won't be a KBPKRP tablebase. The board is flipped appropriately. There are >obviously positions where KBP will win over KRP, which is why there are both >maxDTM for 1-0 and for 0-1. There wouln't need to be 0-1 maxDTM scores when >there would be a seperate KBPKRP tablebase, but there isn't;-) > >Hope I make sense, Laurens. Thanks Laurens. It's not totally clear yet. I will have to think over the concept of flipping the board to figure out why tablebases provide the statistics for either side winning. In the example I gave, white had the rook and black had the bishop. Hence, I don't think there is a need for flipping the board and the tablebases should determine whether white wins, loses, or draws. Is that correct? Thanks. Steve
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