Author: blass uri
Date: 12:27:35 10/09/98
Go up one level in this thread
On October 09, 1998 at 15:22:05, Robert Hyatt wrote: >On October 09, 1998 at 12:08:18, blass uri wrote: > >> >>On October 09, 1998 at 11:58:37, blass uri wrote: >> >>> >>>On October 09, 1998 at 10:37:29, blass uri wrote: >>> >>>> >>>>On October 09, 1998 at 10:25:28, blass uri 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 >>>>>mate in 99 is not a good example because of the 50 move rule but >>>>>I understand that there is a problem here because the opponent may do a move >>>>>that let you only to do mates in an odd number of moves so 2 plies cannot help >>>>> >>>>>Uri >>>> >>>> >>>>you can store mate in N by the number N/2 or N-1/2 >>> >>> >>>of course I mean (N-1)/2 iand not N-1/2 >>>I choose N/2 if N is even and (N-1)/2 if N is odd >>>if 2 plies search are not enough than 4 plies are enough >>>the number of times you should call the tablebases if you have a good order of >>>moves is something like 1000 >>>I do not know the time that you need for it >> >>I think it is less than 1000 because practically for moves that are not best you >>usually discover it after 2 plies and usually there are not many best moves >>so I do not see a reason it is not practical >> >>Uri >> > > >you really only have to probe the databases *after* a capture, because before >the capture is made, you already *know* the mate-in-N score if you start off in >a 3-4-5 piece ending. If you start off in a 6 piece ending, there is no need >to probe until after one capture, and at that point you get an exact distance >to mate and won't search any moves below that capture at all... My idea is that you have less information in the tablebases and then you have to search in a 3-4-5 piece ending but not much only to improve the score from mate in N-1 or N to mate in N-2 or N-3 Uri > > > > > >>> >>>Uri >>> >>> >>> and find by search the right >>>>move >>>>you need all the time to decrease the number >>>>I think that you have to compute sometimes 4 plies forward but if you fast >>>>enough in reading the tablebases then it can help >>>> >>>>Uri >>>> >>>> >>>> >>>>> >>>>>>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 >>>>>>> >>>>>>> >>>>>>> >>>>>>>>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
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