Author: Christophe Theron
Date: 21:56:53 11/05/03
Go up one level in this thread
On November 05, 2003 at 14:15:46, Tony Werten wrote:
>On November 05, 2003 at 11:58:18, Christophe Theron wrote:
>
>>On November 05, 2003 at 03:03:19, Tony Werten wrote:
>>
>>>On November 04, 2003 at 13:58:29, Christophe Theron wrote:
>>>
>>>>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...
>>>
>>>Whatever adjustments you do after no progress, it is only important if the last
>>>fe 5 moves made no progress (or gave checks). If the first 5 moves did this and
>>>then there is a no-check or capture you should do nothing.
>>>
>>>If you trigger from the front (ie root) you'll seriously weaken the engine
>>>because sometimes it is nescessairy to shuffle some pieces around before doing
>>>something, but you will be giving a penalty for that.
>>>
>>>Tony
>>
>>
>>
>>Oh yes. That's how I did it. When I reach a leaf I check if the last X plies
>>where just checks without capture (X=10..12).
>>
>>Probably my definition of "no progress" was not restrictive enough. For example
>>if there is a pawn push, it is not a case of "no progress" I guess.
>
>I would call that a clear sign of progress :)
>
>It's not going to make all horizon effects go away, but it does take care of a
>few annoying ones. And it makes you look like a fool less often. I think I
>decided to implement this after a draw with Gandalf at IPCC in a won position.
>
>Tony
I will definitely give it another try, but I don't expect any spectacular elo
gain. Just, as you said, a way to look less stupid sometimes.
Christophe
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