Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: 10 hour study of game 1 of 6 deep blue vs kasporov

Author: Robert Hyatt

Date: 21:19:33 09/11/01

Go up one level in this thread


On September 11, 2001 at 22:46:43, Vincent Diepeveen wrote:

>On September 11, 2001 at 12:32:27, Uri Blass wrote:
>
>>On September 11, 2001 at 10:43:01, Robert Hyatt wrote:
>>
>>>On September 11, 2001 at 10:27:40, Uri Blass wrote:
>>>
>>>>On September 11, 2001 at 10:19:31, Robert Hyatt wrote:
>>>>
>>>>>On September 11, 2001 at 08:51:20, K. Burcham wrote:
>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>i understand your explanation for the Rg8 and the Rf5 moves bruce.
>>>>>>that deep blue might have seen a loss in both of those lines.
>>>>>>
>>>>>>
>>>>>>i only use the word blunder when during normal game mode or in
>>>>>>      analysis mode the score will jump maybe 2 or more points,
>>>>>>when the next move is made.
>>>>>>
>>>>>>for example in this deep blue blunder    SOS   scores this position
>>>>>>  black is down -1.65. at depth 15.  you can see in the analysis that
>>>>>>the score imidiately jumps and climbs to  +6.41 for white with 44. ...Rd1.
>>>>>>
>>>>>>in the case of the deep junior vs shredder, in the world championship
>>>>>>    i have analyized the 5+ change in score. this was not a single
>>>>>>         move blunder like defined above. in the deep junior game
>>>>>>     shredder didnt have a clue of the deep pawn value and its ability
>>>>>>   to stop them.  then when it finally saw what was really going on
>>>>>>shredder started adjusting its eval very quickly, and the score jumped
>>>>>>   5+ points.
>>>>>>
>>>>>>and i am aware that you already knew all of this----i was just explaining
>>>>>>    my logic for my applicaton of the word blunder.
>>>>>
>>>>>this just means that SOS doesn't understand the position yet.  When I ran
>>>>>this, I got +3.5 or so.  On Rd1 my score gets significantly worse.  Which
>>>>>simply means that they probably searched the alternatives deeper than I did
>>>>>and found that they were bad also.
>>>>
>>>>I rememeber that they admitted that Rd1 was result of a bug.
>>>>Their score for Rd1(-1.80) does not make sense
>>>>in every reasonable depth
>>>>
>>>>They did not play Rd1 because they found
>>>>that the alternative is worse.
>>>>
>>>>Uri
>>>
>>>
>>>I don't believe -180 is the "score"  I think it is an indication of a fail
>>>high.  They didn't resolve a fail high unless a second fail-high occurred,
>>>since knowing that A is better than B is enough to play A.  If you know
>>>that A and B are both better than C, then you have to re-search A and B to
>>>find out which is the better move.  I believe their bug was in the code that
>>>handled this when a time-out occurred.
>>
>>-260 was the score for Rf5 based on their output and it means that the score
>>for Rd1 was more optimistic for black.
>>
>>It seems clear to me that the stupid mistake was result of a bug.
>>
>>I guess that the bug happens only after failing low and not being able to solve
>>the fail low or to finish the iteration on time.
>>
>>Uri
>
>In diep i only play a move that failed high after research is finished.
>if time gets out then i do not play the move failing high at this moment
>i play th ealternative which was searched better.
>
>Still many programs however to today would play the failed high move.
>
>As bob indicates this looks easy case to me without much discussions.


If you fail high, but can't resolve the fail high before running out of time,
I don't see any problem whatsoever with playing the fail-high move.  However,
if you fail low, and resolve that, then fail high on two moves without resolving
either, then playing one of them is _very_ risky...



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.