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Subject: Re: liar

Author: Omid David

Date: 14:15:38 10/04/02

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On October 04, 2002 at 16:52:11, Vincent Diepeveen wrote:

>On October 04, 2002 at 14:57:12, Omid David wrote:
>
>Posted by Omid David (Profile) on October 04, 2002 at 10:34:43:
>
>
>Just today we had a discussion regarding the importance of blockade draw
>detections http://www.talkchess.com/forums/1/message.html?255950
>
>Had Fritz implemented such a scheme, it wouldn't have stepped into the drawing
>variation.
>
>My engine instantly announced draw based on its blocked-draw detection
>heuristic. While Fritz never realized the draw...
>
>Omid.
>---------------------------------
>
>Did you see the position fritz-kramnik?
>
>If you did, do you recognize the position here?

I see now. You thought of a pure static method of detecting blockades, and when
failed to do so, you deemed it "impossible".

Using a (not so complicated) dynamic detection, you can easily figure out that
in Kramnik's position f5 won't break the blockade, whereas in your position, f5
does break it.




>
>
>
>>On October 04, 2002 at 14:27:32, Vincent Diepeveen wrote:
>>
>>>On October 04, 2002 at 11:42:09, Omid David wrote:
>>>
>>>>On October 04, 2002 at 11:38:01, Vincent Diepeveen wrote:
>>>>
>>>>>On October 04, 2002 at 11:36:16, Omid David wrote:
>>>>>
>>>>>>On October 04, 2002 at 11:33:00, Vincent Diepeveen wrote:
>>>>>>
>>>>>>>On October 04, 2002 at 11:25:12, Daniel Clausen wrote:
>>>>>>>
>>>>>>>>On October 04, 2002 at 11:22:05, Vincent Diepeveen wrote:
>>>>>>>>
>>>>>>>>>On October 04, 2002 at 10:34:43, Omid David wrote:
>>>>>>>>>
>>>>>>>>>had fritz implemented such a scheme it would play 300 points weaker
>>>>>>>>>anyway.
>>>>>>>>
>>>>>>>>"Obviously" it's "impossible" to implement such a scheme, because you've tried
>>>>>>>>that already for 5 minutes and it didn't work? SCNR :)
>>>>>>>>
>>>>>>>>Sargon
>>>>>>>
>>>>>>>I played with it with DIEP a few years ago and it performed horrible.
>>>>>>
>>>>>>If you apply such method to each and every node in the search tree, it's natural
>>>>>>that the whole search is slowed down in a horrible manner.
>>>>>
>>>>>no you really are an idiotic programmer if you slow down that
>>>>>much by just a few heuristics.
>>>>
>>>>"just a few heuristic" isn't the case here. It's a complicated (pretty
>>>>time-consuming) algorithm, and this, to make sure its results are 100% correct.
>>>>
>>>>>I already do a lot of scans on the
>>>>>board of diep. a full eval is like 100k clocks. so a scan over
>>>>>the board is not so expensive. i already scan the pawn structure
>>>>>extensively in fact. it's just a few functions i need to turn on
>>>>>to find otu things.
>>>>>
>>>>>>>
>>>>>>>when you have code that 'overrules' other code then you take away hundreds
>>>>>>>of patterns which normally compensate knowledge. it means that if that
>>>>>>>single pattern is incorrect, that you lose directly a game.
>>>>>>
>>>>>>Of course. And that's why your heuristic should be 100% correct and reliable.
>>>>>
>>>>>the problem of the whole chess game is that you have never 100% correct
>>>>>and reliable evaluation except if your opponent is mated.
>>>>
>>>>Wrong. I've conducted hundreds of tests, and in no single case has my heuristic
>>>>returned an inaccurate result. There exist blockades that it fails to detect,
>>>>but it never declares a false draw.
>>>
>>>That's an impossible claim only a beginner can make.
>>
>>If you can't do it, it doesn't mean it's impossible. I say it is possible for I
>>have already done it.
>>
>>
>>>
>>>let's take that 'easy to recognize blocked position from against
>>>kramnik as you mention
>>>
>>>white: Kf1,b3,a4,c4,e5,f4,g5
>>>black: Ka7,a5,b6,c7,e6,g6
>>
>>My engine doesn't detect any draw here.
>>
>>
>>>
>>>black did big effort to exchange to this position. ideally blocked...
>>>
>>>f5 (pawn sacrafice) 1-0
>>>
>>>Vincent
>>>
>>>>Omid.
>>>>
>>>>>
>>>>>>Omid.



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