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Subject: Re: Behind deep Blue

Author: Uri Blass

Date: 11:37:09 10/20/02

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On October 20, 2002 at 14:05:48, Jeremiah Penery wrote:

>On October 20, 2002 at 12:12:26, Uri Blass wrote:
>
>>On October 20, 2002 at 11:29:40, Jeremiah Penery wrote:
>>
>>>On October 20, 2002 at 11:20:55, Uri Blass wrote:
>>>
>>>>On October 20, 2002 at 11:00:42, Jeremiah Penery wrote:
>>>>
>>>>>On October 20, 2002 at 03:41:56, Uri Blass wrote:
>>>>>
>>>>>>On October 19, 2002 at 21:44:49, Fernando Villegas wrote:
>>>>>>
>>>>>>>I have just finished the book by Feng-Hsiung Hsu. In just a shot, from after
>>>>>>>lunch to this time, meal time. Very interesting. You cannot stop he reading.
>>>>>>>First big impression: if this guy and his team had worked just one year more on
>>>>>>>Deep Blue, Garry has been crushed to ashes, to atoms. Yes, because once and
>>>>>>>again Deep Blue appears as an uncomplete device full of bugs and problems,
>>>>>>
>>>>>>
>>>>>>I am surprised that after this people still believe that it's evaluation was
>>>>>>better than the evaluation of Deep Fritz of today.
>>>>>
>>>>>I'm surprised people still think it's evaluation was worse than Fritz of today.
>>>>>But it doesn't matter - I think DB will never play again (stupid IBM), so
>>>>>neither side can EVER win the argument.
>>>>
>>>>The main point is the following:
>>>>"Deep Blue appears as an uncomplete device full of bugs and problems"
>>>
>>>They did have a lot of bugs over the course of the development, but what does
>>>that have to do with the quality of the evaluation?
>>>
>>>>I do not believe that something that is full of bugs and problems can have
>>>>better evaluation than Deep Fritz that was tested more seriously.
>>>
>>>Almost all of the 'bugs' were not in the evaluation.
>>
>>I understood from the discussion that they discovered bugs including bugs in the
>>evaluation in games 1 and 2 of the match against kasparov and fixed them for the
>>rest of the match.
>
>There was an evaluation feature on the hardware that was disabled in the first
>game, which caused DB to think the queen trade was good.  I'm not sure it
>affected the second game, but it's possible.
>
>>Maybe I undertsood wrong and I did not read Hsu's book.
>>I do not want to support Hsu after he left computer chess.
>>
>>I think to buy it only if Hsu returns to computer chess.
>>
>>>
>>>Should I say Fritz has big evaluation 'bugs' because it completely misevaluates
>>>many positions?  Should that be cause to say Fritz has worse evaluation than
>>>some other program(s)?
>>
>>No
>>It is different.
>>
>>Fritz may evaluate wrong something because of lack of knowledge but
>>I believe that the demage from wrong knowledge is often bigger than the demage
>>from lack of knowledge.
>
>Slightly untuned knowledge is not 'wrong knowledge'.
>
>For example, if you tell the program that advancing pawns is good in the
>endgame, it will play better in most cases where that comes up, even if it is
>sometimes wrong due to poor tuning.  Remember, DB evaluation was not completely
>untuned or untested.  Joel Benjamin played a lot of testing games - when he
>found a position the machine played badly, they fixed it.  They also had the
>automatic evaluation tuner, which tuned the evaluation based on short searches
>to more closely match GM analysis.
>
>Would you rather have a program with no king safety (no knowledge), or a program
>that over-evaluates it (untuned knowledge)?

It is not clear

I think that a program with no king safety may be also better.
The question is what is the size of the mistake in the evaluation.

I agree that slightly untuned is better than nothing but the question is if
deeper blue was only slightly untuned.

Uri



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