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Subject: Re: Doesn't appear to work for me (full data)

Author: Omid David Tabibi

Date: 06:10:32 11/21/02

Go up one level in this thread


On November 21, 2002 at 07:18:11, Uri Blass wrote:

>On November 21, 2002 at 06:26:16, Uri Blass wrote:
>
>>On November 21, 2002 at 06:25:17, Uri Blass wrote:
>>
>>>On November 21, 2002 at 04:52:13, Omid David Tabibi wrote:
>>>
>>>>On November 20, 2002 at 22:05:29, Robert Hyatt wrote:
>>>>
>>>>>On November 20, 2002 at 16:55:41, Gian-Carlo Pascutto wrote:
>>>>>
>>>>>>Nullmove in Deep Sjeng uses an algorithm of my own, but I can
>>>>>>switch it back to other systems easily. I did so for running
>>>>>>a few tests.
>>>>>>
>>>>>>I made a version which uses Heinz Adaptive Nullmove Pruning
>>>>>>and a version which uses your verification nullmove.
>>>>>
>>>>>This would seem to be a bit harder than at first glance.  They say that
>>>>>if the normal null-move search fails high, then do a D-1 regular search
>>>>>to verify that, but while in that verification search, no further
>>>>>verification searches are done, meaning that the normal null-move search
>>>>>fail-high is treated just like we do it today..
>>>>>
>>>>>I'm going to experiment with this myself, just for fun, but it seems that you
>>>>>need to pass some sort of flag down thru the search calls indicating that
>>>>>you are either below a verification-search node or not so that recursive
>>>>>verification searches are not done...
>>>>>
>>>>
>>>>Exactly!! (finally someone read the article carefully)
>>>>
>>>>See Figure 3 for detailed implementation (the flag you mentioned which is passed
>>>>down as a parameter for search(), is called 'verify' in the pseudo-code).
>>>>
>>>>At first stage leave alone the zugzwang detection part (the piece of code at the
>>>>bottom of Figure 3). Due to instablilities, some programs might do a needless
>>>>re-search. First let the algorithm work fine in general, and then do the
>>>>zugwzang detection part.
>>>
>>>I let the algorithm to work without zugwzang detection and first results seems
>>>not to be good
>>>
>>>Some positions I get at the same depth and
>>>the only position so far in the gcp test suite that I got at smaller depth for
>>>tactical reasons is
>>>[D]5rk1/1r1qbnnp/R2p2p1/1p1Pp3/1Pp1P1N1/2P1B1NP/5QP1/5R1K w - - 0 1
>>>
>>>I am going to try it in 10 sedconds per move and get resulkts in half an hour.
>>>
>>>Uri
>>
>>should be seconds,results,position
>>I type too fast.
>>
>>Uri
>
>Here are the results of the new version:
>
>1     39     39
>2      9     48
>3      8     56
>4     11     67
>5      6     73
>6      6     79
>7      5     84
>8      4     88
>9      4     92
>10      2     94
>
>results of the old version seem better:
>
>1     40     40
>2     17     57
>3      8     65
>4      7     72
>5      6     78
>6      4     82
>7      8     90
>8      2     92
>9      3     95
>10      1     96
>
>Remember also that I tested the olf version at more than 10 seconds per move so
>if it changed it's mind after 20 seconds from the right move to the wrong move
>the position is counted as a failure.
>
>Uri

Did you use the exact implementation I described in Figure 3?

BTW, you have to compare the algorithms at deeper searches. A fixed 10 ply depth
will be fine.



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