Author: Miguel A. Ballicora
Date: 11:52:59 02/28/01
Go up one level in this thread
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. At the first look I thought it was an interesting idea! but it does not work in the example above... Regards, Miguel > > José C.
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.