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Subject: Re: Deep Blue Jr.

Author: Uri Blass

Date: 23:39:45 07/19/02

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On July 19, 2002 at 19:59:26, Robert Hyatt wrote:

>On July 19, 2002 at 13:45:07, Uri Blass wrote:
>
>>On July 19, 2002 at 13:16:06, Joshua Lee wrote:
>>
>>>I was wondering that if the DB team estimated a rating or over 300 points higher
>>>than the programs at that time on equivalent hardware or equal search, they
>>>weren't clear on that. That would mean 2796 on a P200 and Fritz 7 for example
>>>wouldn't be anywhere near this on a P200. Has anyone seen anything about their
>>>tests against commercial software and does anyone have any opinions about this?
>>>
>>>Granted that Software has improved and that on Todays Fastest Hardware The Top
>>>Programs (provided the SSDF list is that accurate) is on equal footing with Deep
>>>Thought and DB Jr.
>>
>>
>>Why do you think that they may be only equal.
>>I believe that the opinion of most programmers is that
>>the top programs of today are clearly better
>>than Deep thought and deep blue JR.
>>
>>It is known that their search algorithms were bad
>>relative to what is known today
>>(otherwise you could see people who copy their
>>search algorithms with good results when I know that
>>the people who tried to copy the way that they use
>>singular extensions got bad results in games so
>>they do not use it).
>>
>>It is known that they believed some wrong assumptions
>>
>>They believed that null move pruning is dangerous at
>>their speed when the results say that null move pruning
>>is only more productive when the machines are faster.
>>
>>They believed that the brute force depth is not very important
>>at their speed and singular extensions are more important
>>and they were again wrong(programs already
>>have similiar speed to deep thought and they do not use
>>singular extensions in the way that deep thought used them).
>>
>>Their speed simply misleaded them to wrong assumptions
>>that they did not test.
>>
>>Uri
>
>
>That last sentence is simply wrong.
>
>On two counts...
>
>1.  They tested _and_ wrote several papers on their search extensions.  It
>was hardly "not tested".

I assume for this discussion that they tested it in games against
a version without null move pruning and without singular extensions.

Did they test it in games against a version with null move pruning?

It is possible that they could get 2 productive changes:

1)Add null move pruning
2)Not use the singular extensions.

It is possible that 2 is not productive without 1 and
if they did not start by testing 2, they got the wrong conclusions.

Did somebody try to test crafty with their algorithm
(no null move pruning and singular extensions)?

I guess that it is going to be clearly weaker than
the Crafty of today at 120/40 time control.

Uri



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