Author: blass uri
Date: 12:47:21 10/09/98
Go up one level in this thread
On October 09, 1998 at 15:32:52, blass uri wrote: > >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. You do not have to translate it because you start to use the tablebases only after a capture and there is no problem and the tablebases tell you the distance to conversion and you try to do a capture or to move a pawn or doing checkmate as soon as possible without missing the win. Uri
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.