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

Author: Omid David Tabibi

Date: 03:11:54 11/22/02

Go up one level in this thread

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.

Did Aske Plaat compare search times? Did Ernst Heinz compare search times in his
excellent "Adaptive null-move pruning" article?

No, only Vincent who doesn't know anything out of science, calls for such an
erroneous comparison.

BTW, your algorithmic descriptions show that you don't have a good understanding
of algorithms either.

>I suffer plies if i reduce just 1 ply.
>R=2 or R=3 is irrelevant to that.
>>>One final remark: You use standard R = 3 in DIEP. So the search tree constructed
>>>by your program will definitely be smaller than that of verified R = 3. Many
>>>people find standard R = 3 as too risky; but if you are happy with its overall
>>>tactical strength, then I don't recommend you to shift to another method. But
>>>for those who'd like to get greater tactical strength than standard R = 2, and a
>>>smaller search tree than R = 2, I recommend to try verified null-move pruning.
>>Vincent uses R = 3 and complex quiescence search (Vincent, correct me if I am
>>wrong). Maybe your Verified Null-Move gives about the same results like R = 3
>>with a complex quiescence search.
>>_If_ this is true then your approach is simpler and therefore better. Just my
>>two thoughts before going to bed. Good nights.......

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