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Subject: Re: Verified Null-Move Pruning, ICGA 25(3)

Author: Omid David Tabibi

Date: 03:47:00 11/22/02

Go up one level in this thread

On November 22, 2002 at 06:39:24, Uri Blass wrote:

>On November 22, 2002 at 06:11:54, Omid David Tabibi wrote:
>>On November 21, 2002 at 21:21:09, Vincent Diepeveen wrote:
>>>On November 20, 2002 at 17:51:40, Alessandro Damiani wrote:
>>>'verified' nullmove, or in a different implementation but
>>>same algoritm, with just 1 ply reduction is nearly a fullwidth
>>>I did with a bigger reduction of course. that's also very
>>>costly compared to R=3. This was just an experiment carried
>>>out years ago when it was described in ICCA journal. Now
>>>we have same algoritm in a few lines diff algorithm.
>>>I do not see how Omid can just suffer 50% slowdown of his
>>>algorithm. Note he only publishes search depths not
>>>search times. That is wrong.
>>>You must publish search times.
>>You understand nothing out of research, and this is demonstrated by your call
>>for comparing search times.
>1)I understand the point that time can be different but usually comparison of
>times is what I am interested and I trust my computer to be almost at the same
>speed so the error is small.
>Different algorithms may change the number of nodes per second and the
>difference may be dependent on the position so comparison of nodes to get the
>same depth is also not correct.

If you are testing this algorithm on your program, then use fixed time
comparisons. But as someone who wanted to publish as generic results as
possible, I couldn't publish time dependant results.

>2)It is clear for me that your algorithm is clearly better than R=2.
>It is not clear if it is better or worse than R=3 but I agree that with some
>tuning it should be better than R=3.
>Maybe research is going to be enough for it.
>I do not see how research is about detecting zugzwangs.
>The algorithm seems to detect zugzwangs also without research and only searches
>them to reduced depth.

Zugzwang detections through the re-search, is just a bonus ;-)
The core of the algorithm is the middlegame enhancement.


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