Author: José Carlos
Date: 16:03:46 02/28/01
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On February 28, 2001 at 16:55:52, Robert Hyatt wrote: >On February 28, 2001 at 13:32:34, José Carlos wrote: > >>On February 28, 2001 at 13:22:41, Robert Hyatt wrote: >> >>>On February 28, 2001 at 11:10:30, Miguel A. Ballicora wrote: >>> >>>>On February 28, 2001 at 05:56:36, Leen Ammeraal wrote: >>>> >>>>>I am not sure about when to avoid nullmoves. >>>>>I omit it: >>>>>a. when in check >>>>>b. when there are less than 5 pieces (including pawns) on the board >>>>>c. when the last move was a nullmove >>>>>d. at the root node >>>>>Should I also omit it in some other cases, >>>>>for example, when any hashmove (even with a low draft) was found, >>>>>or when beta = alpha + 1? >>>>>Thanks in advance for any help. >>>>>Leen >>>> >>>>Hi Leen, >>>> >>>>Regarding b, I do not know whether what I am doing now is correct but I think >>>>that works for me: >>>>When either black or white had no "long range" pieces (bishop, rook or queen) >>>>I disable null move. The rationale is that one side cannot waste >>>>a tempo in a given position having pawns, king and/or knights making the >>>>position prone to have a zugswang. >>>> >>>>Miguel >>> >>> >>>That seems dangerous. you are white, with a bishop on d5. I am black and I >>>have a pawn on a7 and g7. The bishop is zugged here. If your king can't move, >>>you lose even though you have a long-range slider on the board. And null move >>>will fail high here naturally as not moving is better than having to move and >>>lose. >> >> I don't use null move, so this could be nonsense, but maybe mobility (number >>of available moves) could be used as a threashold for null-move use. For >>example, don't do null-move unless you have at least 10 available moves. >> >> José C. > > >That isn't quite good enough. In the position I gave the bishop has that many >available squares. Except that most lose... Of course. I didn't read carefully enough your example :( But anyway, could it be used added to some other critea (number of pieces, etc...)? José C.
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