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Subject: Re: Maybe i have a solution

Author: blass uri

Date: 07:37:29 10/09/98

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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 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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