Author: Christophe Theron
Date: 10:58:29 11/04/03
Go up one level in this thread
On November 04, 2003 at 02:43:34, Tony Werten wrote:
>On November 03, 2003 at 13:22:42, Christophe Theron wrote:
>
>>On November 03, 2003 at 10:04:32, Will Singleton wrote:
>>
>>>On November 03, 2003 at 02:35:09, Gerd Isenberg wrote:
>>>
>>>>On November 03, 2003 at 02:33:02, Gerd Isenberg wrote:
>>>>
>>>>>On November 02, 2003 at 17:12:38, Will Singleton wrote:
>>>>>
>>>>>>On November 02, 2003 at 16:52:49, Gerd Isenberg wrote:
>>>>>>
>>>>>>><snip>
>>>>>>>>In the same vein, the following position has always been a nightmare for Tiger:
>>>>>>>>
>>>>>>>>[D]8/1KP5/3q2k1/8/6p1/8/8/8 b - -
>>>>>>>>
>>>>>>>>This position comes from a real game between the Modular Game System Sargon 2.5
>>>>>>>>and Mike III, played in September 1980 during the Personal Computer World Fair.
>>>>>>>>Mike III continued the game with a long series of checks leading to a draw.
>>>>>>>>
>>>>>>>>Chess Tiger is not smarter than Mike III here. It is something that I had fixed
>>>>>>>>in the 16 bits version, to the expense of some added complexity in the passed
>>>>>>>>pawns evaluation code. I have not transfered this code to the 32 bits version
>>>>>>>>because it was not general enough (add another black pawn and the code did not
>>>>>>>>work).
>>>>>>>>
>>>>>>>>I am interested in results of other (amateur and commercial) programs.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> Christophe
>>>>>>>
>>>>>>>Hi Christophe,
>>>>>>>
>>>>>>>IsiChess on AMD XP2.6+ first shuffles around with Qb4+, Qxc7 and Qd7.
>>>>>>>After 5 seconds at depth 13 Qxc7 came up. Mate in 14 resp. 12 after one minute
>>>>>>>and 1:10. I guess a matter of won KPK eval.
>>>>>>>
>>>>>>>Cheers,
>>>>>>>Gerd
>>>>>>
>>>>>>Sure, but I'm not sure CT was referring to finding the mate as the problem. CT
>>>>>>seems to have some problem understanding that KQK is better than KQKP, that's
>>>>>>all I can figure.
>>>>>>
>>>>>>Will
>>>>>
>>>>you mean won KPK against KQPKP? I use interior node recognizers and assign
>>>>shlightly more than queen advantage in won KPK. Additionaly there is a
>>>>heuristic, that reduces score a bit (e.g. abs(delta material) / X) if a lot of
>>>>checks occur with "no progress".
>>>> ^^^^
>>>>Gerd
>>>
>>>I do that too, but it's constrained to several consecutive checks that don't
>>>reset the fifty-move counter. Seems to help in some positions, but I'm not sure
>>>how generally effective it is.
>>>
>>>Will
>>
>>
>>
>>That's exactly what I have tried, with different values for X and the number of
>>consecutive checks needed to trigger it.
>>
>>It has always weakened my program. Not by much, but I expected a minor gain, not
>>a minor loss!
>
>Make sure your trigger is counted from the back, not the front. ( I don't want
>to make it too easy :)
>
>Tony
I really don't understand what you mean...
Christophe
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