Author: blass uri
Date: 12:32:52 10/09/98
Go up one level in this thread
On October 09, 1998 at 15:15:22, Robert Hyatt wrote: >On October 09, 1998 at 09:56:20, blass uri wrote: > >> >>On October 09, 1998 at 09:35:55, Robert Hyatt wrote: >> >>>On October 09, 1998 at 08:54:02, blass uri wrote: >>> >>>> >>>>On October 09, 1998 at 08:10:51, blass uri wrote: >>>> >>>>>I think it is better to store the number of moves to win in the tablebases only >>>>>if this number is divisible by 2 because otherwise you can compute the number of >>>>>moves by search. >>>>> >>>>>Maybe it is possible practically to store it only if it is divisble by 3 or 4 (I >>>>>do not know what is the speed of reading the tablebases from harddisk) >>>>> >>>>>Uri >>>>I think it is easy to save at least 1 bit per position by this idea if in >>>>positions when there is win in N when N is divisible by 2 you store win in N/2 >>>>and in positions when there is a win in N when N is not divisible by 2 you store >>>>a win in 1(you can discover by search that it is not truth). >>>> >>> >>> >>>this is imposible to do. KNN vs KP is a mate in over 100 moves. How do >>>I separate mate in 50 from mate in 100? I certainly can't search to find >>>this out... >> >>I mean that when you store the number N/2 you mean win in N >> >>you have only to search 2 plies because if you have mate in 99 >>the tablebases will tell you the number 1 >>You know by search that there is no mate in 2 but you have in the tablebase >>mates in 98 so by searching 2 plies you can read from the tablebases the mate >>in 98 after 2 plies. >>Searching 2 plies and reading the tablebases after every 2 possible plies(you do >>not need every 2 possible because of the alpha beta is not impossible >>> >>> > > >How do I tell the difference from a mate in 49 and a mate in 48. And *that* >is critical, because if I keep choosing mates in 49 I am going to draw. In >fact, a mate in 49 that I think is a mate in 48 is probably exactly enough to >draw if there are exactly 50 moves to the mate to start with... > > > >>> >>>>By this idea you can use the same number of bits to every position. >>>> >>>>If you want to use different number of bits to every popsition you must add 1 >>>>bit >>>>to tell if the is a position with win in number of moves divisible by 2 or not. >>>> >>>>of course if you lose it is not important to know the number of moves. >>>> >>>>I use the word win and not mate because it is a mistake to use mate >>>>because of the 50 move rule >>>> >>>>Uri >>> >>> >>>distance to conversion has the same 50-move problem... >> >>why? >>If the distance is more than 50 then you know it is a draw. >> >>Uri > > >but if it is *less* than 50 you don't know this. Yet you can find a score >that is "conversion in 30" after you have played 30 non-capturing moves and >it ends up wrong there too... ie both have problems with the 50-move rule >the way they are computed... You know the history of the game so if you find a score that is conversion in 30 after you have played 30 non capturing moves then you translate it to conversion at 60 The target is to achieve conversion as soon as possible and I do not see problems.
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