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Subject: Re: mate threat extension/null move

Author: Stuart Cracraft

Date: 14:29:57 09/29/04

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On September 29, 2004 at 16:06:36, Uri Blass wrote:

>On September 29, 2004 at 14:51:16, Dan Honeycutt wrote:
>
>>On September 29, 2004 at 14:16:23, Stuart Cracraft wrote:
>>
>>[snip]
>>>
>>>WAC 141 takes me a shade over 24,000,000 nodes, a fully completed 7 ply search,
>>>to find Qxf4 with all the above improvements, still the same amount of
>>>time as without:
>>>
>>>Alpha=-1332 Beta=-532 Maxdepth=9999999 MaxTime=1410065407
>>> 1/11  g2f1  0.00 -953      945 g2f1 f4d5
>>>                                g2f1 f4d5
>>> 2/12  g2f1  0.01 -953     1653
>>>                                g2f1 f4d5 c1g5
>>> 3/12  g2f1  0.02 -953     5073
>>>                                g2f1 f4d5 c1g5 d5f6
>>> 4/20  g2f1  0.09 -953    19924
>>>                                g2f1 f4d5 b3d5 c6d5 c1c7 d6c7 f1g1
>>> 5/22  g2f1  0.71 -953   170357
>>>                                g2f1 b5b4 b3a4 f4d5 f6g5 d5e7
>>> 6/26  g2f1  2.85 -953   617222
>>>                                g2f1 b5b4 mtmt
>>> 7/32> g2f1 56.60 -553 13644478 g2f1 e8c8 c1b1 f4d5 b1e4 d6b4 f6e5 c7b6
>>>                                g2f1 e8c8 c1b1 f4d5 b1e4 d6b4
>>> 7/34  c1f4 97.33 5113 24161497 c1f4 e8e6 f4g5 d7e7 b3e6 e7e6 h1d1 d6e7 f6e7
>>>                                c1f4 e8e6 f4g5 d7e7 b3e6 e7e6 h1d1
>>> 8/34  c1f4 115.59 5113 27838968
>>>                                c1f4 e8e6 f4g5 d7e7 b3e6 e7e6 h1d1
>>> 9/34> c1f4 197.37 5513 48705672
>>>                                c1f4 e8e6 f4g5 d7e7 b3e6 e7e6 h1d1 mtmt
>>> 9/... still searching
>>>
>>>Stuart
>>
>>Doesn't look like the program has actually found Qxf4.  e8e6 is not the next
>>move.
>>
>>Dan H.
>
>The next move is not important
>
>Every move is losing and the question what is the next move in the program pv is
>dependent on extensions.
>
>It is clear that too many extensions were used because the program needs so many
>nodes to finish depth 7 and the selctive depth is too high(depth 7/34).
>
>I believe that the recapture extension that is used is bad if it helps to solve
>the problem at depth 7 with so many nodes but the only test to be sure is games.
>
>Uri
>Uri

I considered your last point as well and removed RECAP. The problem cannot
be resolved without it after 10+ minutes. With it, it solves at 95 seconds
at ply 7.

My main search escape-from-checks and quiescence escape-from-checks are
unlimited.

I do not search checking moves except in main search or unless a move
out of check in quiescence is a checking move.

Stuart



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