Author: Ricardo Gibert
Date: 00:52:13 02/04/05
Go up one level in this thread
On February 04, 2005 at 03:50:37, Vincent Lejeune wrote: >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 Curse you! You beat me to the punch by 5 seconds! ;)
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