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Subject: Re: null-move vs non-null-move

Author: Uri Blass

Date: 10:09:45 10/10/02

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On October 10, 2002 at 12:01:43, Sune Fischer wrote:

>On October 10, 2002 at 09:09:21, Uri Blass wrote:
>
>>On October 10, 2002 at 06:51:47, Alessandro Damiani wrote:
>>
>>>On October 10, 2002 at 02:01:51, Uri Blass wrote:
>>>
>>>>On October 09, 2002 at 23:06:48, Robert Hyatt wrote:
>>>>
>>>>>
>>>>>
>>>>>I had to stop the experiment sooner than I wanted, but I did find some
>>>>>interesting things out.
>>>>>
>>>>>1.  at _very_ fast time controls (40 moves in 1 minute) null-move completely
>>>>>destroys non-null-move
>>>>>by a ridiculous margin.  (this ended something like 60 wins, 5 losses, 8 draws)
>>>>>
>>>>>2.  At longer time controls (40 moves in 10 minutes) non-null-move catches up
>>>>>somewhat.  It still loses
>>>>>far more than it wins, but not _nearly_ so bad as test 1.  (this was closer, but
>>>>>with fewer games played)
>>>>
>>>>It seems based on your data that null move is more important for blitz and not
>>>>for long time control.
>>>>
>>>>Interesting to know also the difference in plies
>>>>
>>>>If I compare depth after 3 minutes of search then I see for deep Fritz 3-5 plies
>>>>difference at 3 minutes per move between selectivity 0 and the default value 2.
>>>>
>>>
>>>By using a program with unknown source code you cannot be sure that
>>>selectivity=2 is only related to null-move.
>>>
>>>Alessandro
>>
>>Ok
>>I tested movei(R=3) against Movei(R=0) in the same positions and I get after 10
>>minutes of search in every position depthes 12,15 with null move against depthes
>>10,11 without null move.
>>
>>Difference of 2-4 plies that may be even bigger if I use null move in a more
>>efficient way.
>>
>
>Depth doesn't mean a thing when you prune, try R=4 or R=5, you will reach even
>larger depth, and maybe also solve the testsets faster, but don't forget to see
>if it _playes_ better! ;)
>
>-S.

I still did not try R=4 but it seems that R=3 is better than R=2 based on my
experience mainly at long time control.

Uri



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