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Subject: Re: Some analysis of Deep Fritz for kasparov-deeper blue first game

Author: Uri Blass

Date: 00:19:05 05/07/01

Go up one level in this thread


On May 06, 2001 at 23:53:59, Robert Hyatt wrote:

>On May 06, 2001 at 19:46:43, Vincent Diepeveen wrote:
>
>>On May 06, 2001 at 02:28:14, Uri Blass wrote:
>>
>>>I gave Deep Fritz to analyze similiar number of nodes to Deeper blue and Deep
>>>Fritz seems to be clearly better in tactics.
>>>
>>>Deep Fritz needs only 191728 knodes to see the line Rf5+ Ke3
>>>It means only 1 second if I asuume 200,000,000 nodes per second.
>>>
>>>I believe that Rf5+ failed low at depth 17 for Deeper blue for the reason Ke3.
>>>The pv of deeper blue at smaller depthes is Rf5+ Ke2
>>
>>11 ply for those who are good in math and a bit more real to the world.
>
>Uri is correct.  Unless you _still_ dispute the direct statement(s) by the
>Deep Blue team.
>
>
>
>>
>>>Deep Fritz probably does better extensions than Deeper blue because Deep Fritz
>>>see big fail low at depth 16.
>>
>>Fritz hardly has dangerous extensions.
>>
>>Diep has. note i am not extending passers much. Just a bit and only
>>now and then.
>>
>>The Big fail low comes at 12 ply for DIEP. Then it sees Rf5 is losing
>>because of Ke3 though it initially wants to go e3. Then i did a state
>>check to see what the deepest search lines are. You can see it
>>yourself:
>
>
>What does any of this matter?  Their score was bad... yours is bad, black
>is lost...  I don't see where you see it any faster than they did...

I see that Deeper blue score is clearly better than the score of other programs
after search.

Deeper blue said only 2.1 pawns for white after 73 seconds of search when other
programs has no problem to see clearly better score for white.

I can explain 1 pawn difference or even 1.5 pawns difference by different
evaluation but the difference between Crafty's evaluation(4.22) and their
evaluation(2.1 after 73 seconds)  is more than 2 pawns(I mean to the evaluation
of Rf5+) and it can be explained only by the fact that crafty could see deeper.

Their score at depth 15 is only 1.63 for white so if you compare same depth then
it is clear that Crafty did better extensions than deeper blue.

If you do not like depth 15 of move 43 because of the bug that cause deeper blue
to play Rd1 you can take depth 11(6)=17 at move 42 abd you find there a score of
only 1.36 pawns for white.

I assume that 11(6) means depth 17 with futility pruning and in this case the
top programs of today clearly do better extensions than deeper blue.

Uri



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