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Subject: Re: Draw due to lack of blockade detection...

Author: Omid David

Date: 14:12:11 10/04/02

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On October 04, 2002 at 16:40:04, Vincent Diepeveen wrote:

>On October 04, 2002 at 15:39:36, Omid David wrote:
>
>So you are declaring that months of work of me some years ago is
>completely stupidly done because you can do it 'perfect' like the
>EGTBs can do it?

No, I can't do it perfect. There are many blockaded positions which my method
fails to detect. But when it _does_ detect them, it has a 100% accuracy.



>
>>On October 04, 2002 at 15:17:45, Joachim Rang wrote:
>>
>>>On October 04, 2002 at 14:39:05, Vincent Diepeveen wrote:
>>>
>>>>On October 04, 2002 at 14:34:46, Joachim Rang wrote:
>>>>
>>>>>On October 04, 2002 at 14:21:16, Vincent Diepeveen wrote:
>>>>>
>>>>>>On October 04, 2002 at 11:48:06, Omid David wrote:
>>>>>>
>>>>>>How many times must i say the same thing?
>>>>>>
>>>>>>Suppose i have 200 patterns to adjust my score.
>>>>>>
>>>>>>Now 1 pattern can undo all those 200 patterns.
>>>>>>
>>>>>>I'm then either an idiot then to have those 200 patterns,
>>>>>>or to use that one pattern, if it is in 50% of the cases wrong.
>>>>>>Even if it is in 80% of the cases right :)
>>>>>
>>>>>I can't understand what you are trying to say.
>>>>>Suppose you have 200 patterns and add another drawing-detection pattern a la
>>>>>Omid. This 201st pattern overrides the 200 other patterns if certain
>>>>>circumstances are met (which means in certain positions). The pattern does not
>>>>>change any evaluation if certain circumstances aren't met. Suppose you can
>>>>>describe the circumstances correctly, the drawing pattern overrides the 200
>>>>>other patterns only in the correct positions. The other 200 patterns you need
>>>>>for the other positions.
>>>>>
>>>>>regards
>>>>>
>>>>>Joachim
>>>>
>>>>You still think chess is like mathetmatics, so
>>>> 1 = 1
>>>>
>>>>and
>>>>
>>>> 2 = 2
>>>>
>>>>then whey aren't there engines playing perfect chess?
>>>
>>>yes you may be right, I'm quite a newbie in computer chess and a weak player
>>>too. But why are you angry at me, instead of telling me, where I don't see the
>>>point (which should be a bit more concrete than "you are to stupid to understand
>>>it").
>>
>>The fact that you are a newbie doesn't have anything to do with this case. Your
>>reasoning was completely correct.
>>
>>I'm telling you, there *is* a way to detect blockades with 100% accuracy, i.e.
>>there might be blockades in which it doesn't detect and that's fine (you'll do
>>regular search), but it *never* announces draw wrongfully.
>>
>>It *can* be done, for I have done it, and I believe most of the programmers here
>>(including Vincent, if he thinks a little before announcing it "impossible") can
>>do it.
>>
>>
>>>
>>>If I understand you correctly you doubt that there is a way to detect such draws
>>>100% correctly. Okay I'm not an expert in this area you may be right.
>>>
>>>>
>>>>> >
>>>>>>>On October 04, 2002 at 11:34:39, Vincent Diepeveen wrote:
>>>>>>>
>>>>>>>>On October 04, 2002 at 11:26:51, Omid David wrote:
>>>>>>>>
>>>>>>>>slowing down the search is not the problem. the problem i
>>>>>>>>explained in email to sargon
>>>>>>>
>>>>>>>So I assume the problem is that it's not 100% reliable, and may return
>>>>>>>inaccurate estimates. Right?
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>>>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.
>>>>>>>>>
>>>>>>>>>It depends on how you implement it without slowing down the search
>>>>>>>>>significantly, and that's what I'm currently working on...
>>>>>>>>>
>>>>>>>>>It's obvious that applying the whole heuristic on each and every node is too
>>>>>>>>>expensive. But a wise application of it, could detect many draws without any
>>>>>>>>>significant impact on the total speed.
>>>>>>>>>
>>>>>>>>>Omid.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>>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.



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