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

Author: Robert Hyatt

Date: 13:19:00 11/21/02

Go up one level in this thread

On November 21, 2002 at 05:14:53, Alessandro Damiani wrote:

>On November 20, 2002 at 18:59:59, Uri Blass wrote:
>>On November 20, 2002 at 17:51:40, Alessandro Damiani wrote:
>>>>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.......
>>I do not believe that it gives the same results.
>I wrote "about the same result" which is not equal to "the same result". And I
>added "maybe". These words tells you that I am just guessing, nothing more,
>nothing less.
>>I do not know which algorithm is better but the
>>algorithms are different.
>Right, to know and to guess are two different things. I am in the guess-phase.
>>I believe that a third algorithm may be better than both of them.
>BTW I won't use it. My preferred algorithm is Alpha Beta Conspiracy Search
>(ABC), and ABC already contains Verified Null-Move in a different way.
>BTW Verified Null-Move looks like an improvement of Fail High Reductions by the
>authors of Zugzwang.

If you mean because while verifying at one node you don't verify anywhere deeper
agree.  I tried the FHR and threw it out as too expensive when it first surfaced
years ago.  This approach bears some testing however...

Unfortunately I have not yet made any progress.  Been busy writing
justifications for the
new ftp server to house all of Eugene's 6-piece EGTB stuff.  :)

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