Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: mate threat extension/null move

Author: Michael Henderson

Date: 15:52:45 09/29/04

Go up one level in this thread


On September 29, 2004 at 17:29:57, Stuart Cracraft wrote:

>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

I think there is something wrong with your search.  -953 is too large of a
losing score for g2f1, it should be around -100 to -300.  Can you post the
complete variation that leads to this score? with Triangular array you can by
not cutting off with a PV entry. h1d1 in the PV looks strange also.

Recapture extension should not be helping you here, I believe.  I don't think
even captures are hiding anything useful.

Michael



This page took 0.04 seconds to execute

Last modified: Thu, 07 Jul 11 08:48:38 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.