Author: Uri Blass
Date: 12:41:51 01/30/02
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On January 30, 2002 at 14:55:16, Dann Corbit wrote: >On January 30, 2002 at 05:07:02, Uri Blass wrote: >[snip] >>and side to move that make 16 "reflections" based on the definition of having >>practically the same position(this is not the definition of Les). >> >>b1 a2 a7 b8 g1 h2 h7 g8 are symmetric when there are no pawns and in all of >>these cases you can change the side to move. > >In the encoding scheme that Les invented, you also *multiply* this by the number >of ways the sliding piece can go to the solution square. > >Suppose that a rook can mate in 12 if he slides to the solution position. There >are up to 13 other squares he can move to the same solution sqare from other >than the square that he is sitting on. So in this case, there are up to 16 * 13 >= 208 board positions that will all have a mate in (12 or better). > >Now, Les only saves *one* of these positions [the smallest one lexically]. All >of the others can be generated from that one. Along with all of their key moves >and all of their centipawn evaluations. > >With a queen, it is even more drastic. > >So that is how he saves space. Work it out for KQK and see what the savings is. I am not interested in KQK in KQK I do not need tablebases to win. it may be more interesting if it can save significant space in endgames like KQP vs KQ when there are a lot of draws saving one position and saying this is winning so 100 other positions are winning is not going to help much here. I am also not interested in generating all the positions from one positions in the set that is the smallest one. Practically the situation that you have is getting one position that is usually not the smallest laxically. I do not understand how do you get practically from this position the winning move. Uri
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