Computer Chess Club Archives


Search

Terms

Messages

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

Author: Robert Hyatt

Date: 06:57:12 05/07/01

Go up one level in this thread


On May 07, 2001 at 06:15:24, Vincent Diepeveen wrote:

>On May 06, 2001 at 16:11:11, Uri Blass wrote:
>
>>On May 06, 2001 at 14:44:40, Paul wrote:
>>
>>>On May 06, 2001 at 14:26:52, Uri Blass wrote:
>>>
>>>>On May 06, 2001 at 14:25:58, Uri Blass wrote:
>>>>
>>>>>On May 06, 2001 at 14:16:04, Paul wrote:
>>>>>
>>>>>>On May 06, 2001 at 14:01:22, Terry McCracken wrote:
>>>>>>
>>>>>>>On May 06, 2001 at 05:40:02, Uri Blass wrote:
>>>>>>>
>>>>>>>>On May 06, 2001 at 03:51:47, Paul 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
>>>>>>>>>>
>>>>>>>>>>Deep Fritz probably does better extensions than Deeper blue because Deep Fritz
>>>>>>>>>>see big fail low at depth 16.
>>>>>>>>>>
>>>>>>>>>>Deep fritz also can see another fail low for Rg8 at depth 22 when deeper blue
>>>>>>>>>>could get only depth 17 after similiar number of nodes.
>>>>>>>>>>
>>>>>>>>>>I do not believe that you lose more than 2-3 plies from null move pruning(my
>>>>>>>>>>test suggest that you do not lose even 1 ply at small depthes so I guess that
>>>>>>>>>>Deep Fritz can search deeper because it is a better software.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>kasparov - Deeper blue
>>>>>>>>>>4r3/8/2p2PPk/1p1r4/pP2p1R1/P1B5/2P2K2/8 b - - 0 1
>>>>>>>>>>
>>>>>>>>>>Analysis by Deep Fritz:
>>>>>>>>>
>>>>>>>>><snip>
>>>>>>>>>
>>>>>>>>>I remember from the time this match was played that this was due to some bug
>>>>>>>>>which was subsequently corrected, so there's not much sense in discussing this
>>>>>>>>>position. Any other will do, but not this one. Even my program finds Rf5+ in
>>>>>>>>>seconds.
>>>>>>>>>
>>>>>>>>>Groetjes,
>>>>>>>>>Paul
>>>>>>>>
>>>>>>>>I know about the bug
>>>>>>>>
>>>>>>>>I am not talking about finding Rf5 but about finding the reason that Rf5+ is
>>>>>>>>losing.
>>>>>>>>
>>>>>>>>I mean to find the fact that line Rf5+ Ke3 that is good for white.
>>>>>>>>Deeper blue could not see it at iteration 16 and the logfile suggests Rf5+ Ke2
>>>>>>>>
>>>>>>>>Deeper blue had a fail low at iteration 17 and the logfile does not give a line
>>>>>>>>for Rf5.
>>>>>>>>I guess that it failed low because of Ke3.
>>>>>>>>
>>>>>>>>The point is that Deeper blue is slower than top programs in failing low.
>>>>>>>>
>>>>>>>>Deeper blue could not find Rf5+ Ke3 after 73 seconds when Deep Fritz can find it
>>>>>>>>in a few minutes on p800 and it means that it could find it in less than second
>>>>>>>>if it could search 200M nps.
>>>>>>>>
>>>>>>>>Uri
>>>>>>>
>>>>>>>I think you're right Uri if you dragged out Deep Blue of May 1997 or at least
>>>>>>>close.
>>>>>>>But you have to remember it was 1997 and if my memory serves me correctly,
>>>>>>>Kasparov was very puzzled by Rf5+ as programms just didn't look at this move
>>>>>>>at that time, except for Deep Blue in such a short time frame.
>>>>>>>At least that's what I remeber from what Kasparov mentioned in his notes. Not
>>>>>>>the exact words, I'm not quoting what Kasparov said or wrote but just what I
>>>>>>>remember from that time, on the "Old Club Kasparov" hosted by IBM which is long
>>>>>>>gone.
>>>>>>>I also remember after many hours of analysis with "computers of the day"
>>>>>>>P6-200's, that Kasparov finally "understood" why Deep Blue played the "Human"
>>>>>>>looking move, Rf5+.
>>>>>>>Actually, I think Kasparov wasted too much energy trying to understand Deeper
>>>>>>>Blue which I believe exhausted him. Hence, his less than stellar preformance
>>>>>>>in Game 2 and the rest of the match.
>>>>>>>
>>>>>>>Terry McCracken
>>>>>>
>>>>>>Deep Blue didn't play Rf5, it played Rd1! Uri wants to analyze the evaluation
>>>>>>out of the log of Deep Blue ignoring the bug. Seems impossible to me. :)
>>>>>>
>>>>>>Paul
>>>>>
>>>>>I believe that the bug happened only after failing low on Rf5.
>>>>>
>>>>>The logfiles do not give a score for Rd1 so I believe that the bug is not
>>>>>relevant for Rd1
>>>>
>>>>I mean of course is not relevant for the lines before Rd1
>>>>>
>>>>>The last line of the logfile of game 1 begins with
>>>>>11(6)[Rf5](-260)v [find a move]
>>>>>
>>>>>I never see the words find a move in deeper blue in other cases and it suggests
>>>>>that the bug happened only after Deeper blue failed low.
>>>>>
>>>>>The line for Rd1 is also a short line when previous lines are long lines so I
>>>>>trust the analysis of deeper blue at depth<17.
>>>>>
>>>>>Uri
>>>
>>>Uri, you don't know what the bug was, I don't know what the bug was, and now out
>>>of all the positions you could analyze, you pick the one where it's certain that
>>>there is a bug in it. Why?
>>>
>>>Seems to me there are hundreds of other positions more useful & interesting for
>>>analysis, for example from the (by Deep Blue at least) excellently played game
>>>6? But if you want to ... go on by all means. :)
>>>
>>>Greetings,
>>>Paul
>>
>>I already analyzed another position from the first game and unfortunately nobody
>>responded to the analysis and the discussion was about the question if Deeper
>>blue did processing at the root.
>>
>>see http://www.icdchess.com/forums/1/message.shtml?167877
>>
>>Uri
>
>Uri, for all programmers you had proven the point very clearly.


No, he didn't "prove" anything at all.  You can't take output from a program,
output that is incomplete due to the way they produce their PV, and then try to
draw conclusions from it.  Any more than you can take evaluations and draw
conclusions from them without any idea of what the evaluation looks like
internally...



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.