Author: Vincent Lejeune
Date: 00:50:37 02/04/05
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On February 04, 2005 at 03:44:57, Uri Blass wrote: >On February 04, 2005 at 03:41:01, Uri Blass wrote: > >>I find that there are some illegal positions in nalimov tablebases like the >>following position because there is no possible last move of white. >> >>[D]3K4/8/8/3R4/3kR3/8/8/8 b - - 0 1 >> >>Note that the following position is legal(last move of white could be under >>promotion to a rook) >>[D]kR1K4/8/R7/8/8/8/8/8 b - - 0 1 >> >>I wonder if somebody cared to count the number of legal positions with 6 or less >>pieces. >> >>A position with 4 pieces is illegal if it cannot be reached from position that >>is not obviously illegal of 5 piece or less pieces so it is possible to count >>the number of 4 piece positions that can be reached from positions of 5 or 4 >>pieces. >> >>I am not sure if all of them are legal but I cannot think about an example when >>a position with 4 pieces is illegal and can be reached from illegal 5 piece >>position. >> >>note that it is different with 5 piece position and 6 piece position and here is >>an example. >> >>[D]6k1/8/8/8/8/8/3P1P2/4B1K1 w - - 0 1 >> >>illegal >> >>can be reached from >>[D]6R1/5k2/8/8/8/8/3P1P2/4B1K1 b - - 0 1 >>also illegal. >> >>Uri > >In a second thought > >This is illegal position that can be reached from illegal 5 piece position > >[D]8/8/8/8/8/1k6/1P6/B1K5 w - - 0 1 > >Uri the 3 last positions are legal in Fischer-random-chess
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