Author: Mathieu Pagé
Date: 10:02:01 12/17/04
Go up one level in this thread
On December 16, 2004 at 21:30:41, Les Fernandez wrote: >On December 16, 2004 at 17:05:48, Nino wrote: > >>On December 16, 2004 at 16:38:07, F. Huber wrote: >> >>>On December 16, 2004 at 16:22:11, Nino wrote: >>> >>>>I came across your post not to long ago about some kind of special utility for >>>>mates. HAve not seen anything about it nor did you say much about it. Can you >>>>please tell me more about it and why was the results of those test positions >>>>never reported. I would be interested in knowing more about this utility and >>>>the results of the positions. Does anyone else know about this? >>>> >>>>Kindly, >>>> >>>>DM >>> >>>Have a look here: >>> >>>http://www.talkchess.com/forums/1/message.html?400706 >> >>I saw the post but was hoping to have Dann or anyone else tell me a little more >>about it. Does anyone know anymore about it? Perhaps a buit more detail about >>what it is and what it can do. >> >>Thanks >>> >>>Regards, >>>Franz. > >Hello Nino, > >Well like Franz and Dann mentioned before I am just cleaning up some of the code >and will make it available soon. I dont spend much time on it since I am busy >during the day but do work on it at night. Basically what this utility does is >find mate positions much faster (I believe) then what is done normally. It >takes advantage of a special binary format which can store an entire EPD string >along with side to move, all the pieces (b/w), their locations on the board, >castling rights, enpassant, ce and pv. Whats nice about this special binary >format may be explained better with an example: Lets say you have the following >epd string (not a real position, just for example): > >3rn3/2p4k/8/8/3Q4/R7/Nn3P2/7K w - - pv Qd1; ce 32740; > >As an average I can store this position using about 9 bits. This is >accomplished by taking advantage of the special binary format I have adopted. >Whats nice about this as Dann has mentioned is that this utility can compose new >mates also. Another interesting thing to note is that however many bits it >takes me to store the above ficticious position in my special binary format I >can store up to an additional 108 positions using not even 1 extra bit. So for >example if it takes me 182 bits to store the above "1" position I can add an >additional 108 positions to it and it would still only require 182 bits. FYI the >least amount of bits I need for K K is 110 bits and the worse case scenarion >(all pieces on board) would need 380 bits. These numbers may seem high but I >assure you that an approximation as to how many bits are needed using my binary >format would be closer to for K K ~ 5 bits and full board ~ 19 bits. As >mentioned above it not only stores the pieces but everything else in the >standard EPD string. > >HTH, > >Les Hi Les, Did you mean bytes when you say bits ? It's hard to believe for me that you encoded a position in about 19 bits (or 2.375 bytes). Mathieu Pagé
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