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Subject: Re: NullMove efficiency

Author: Matthias Gemuh

Date: 01:52:26 12/06/03

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>>>
>>>
>>>The ratio nullmove_cutoffs / main_search_moves_searched is only 15%...20%
>>>in my program. Is this extremely low ?
>
>I am not quite sure I understand what you are measuring here.  Is
>main_search_moves_searched
>the total number of non-qsearch nodes ?


Right. I know that the value is almost meaningless as the cutoffs are at
different depths, as well as the moves searched.




>The main weakness of BigLion and Taktix seems to be their search.

Tord, you know I value each word from you more than pure gold.
Thanks for this revelation.



>With your big and high-quality eval, you
>should be able to search about 2 plies deeper in the middle game by using the
>eval to do forward pruning and/or depth reductions.

I shall try to think.



>One thing I have noticed is that your engines' behaviour in the first few
>iterations is rather unusual.  In almost all other engines, the first 4 or 5 plies flies by so
>quickly that it is not possible to follow the lines on the computer screen.  In BigLion and Taktix,
>each of the first 5 plies take about a quarter of a second to complete.
>This is strange in two different ways:
>It is strange that a 1-ply search should take as much as a quarter of a second,
>and it is
>strange that the amount of time needed is apparently almost linear (rather than
>exponential)
>as a function of the search depth.  For bigger search depths, things begin to
>look more
>normal.  What's happening in the first few iterations of your search?
>


I shall look more closely.


Thanx,
Matthias.




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