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Subject: Re: Deep Blue and the

Author: Eugene Nalimov

Date: 10:38:57 11/16/98

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On November 16, 1998 at 09:55:46, Amir Ban wrote:

>On November 16, 1998 at 02:13:01, Ed Schröder wrote:
>
>
>>>Yes, you got it right.
>>
>>>The PV for Deep-Blue on all iterations except the last starts 36.Qb6 Qe7
>>>37.axb5 Rab8 38.Qxa6 e4 39.Bxe4 Qe5. In the last iteration, there's no PV.
>>
>>Thanks for posting the main variation. I clearly remember the end position
>>again. Based on this impressive main variation I can come to no other
>>conclusion other then that Deep Blue must have a speculative king safety.
>>
>
>I'm not ruling this out as an hypothesis, but please tell me: How does a
>speculative king safety agree with moves such as g5 in the 1st game, b4 in the
>4th game, and a generally solid style throughout the match ?

About a year ago Murray Campbell gave a lecture on Deep Blue
at MS. If I remember it correctly, I posted summary of that
lecture at r.g.c.c.

According to that lecture, they significally increased king
safety bonus after game 1. Unfortunately, I don't remember,
was it done before or after game 2.

Other story is that in the end of game 1 (if I remember it
correctly), in already lost position, DB made very bad move,
and DB team immediately resigned the game. Move was made
because of the bug in the program (C macro was wroten
incorrectly, and after the expansion program made wrong
choice). All the "specialists" who consulted Karparov never
thought about bug possibility. Instead they explained that
DB calculated deep enough to see that all other moves were
losing too, so it choose -5 now instead of -6 in the future
(numbers are mine, for explanation purposes only). That's
one of the reasons why Kasparov beleived that DB see the win
in game 2 - 'it saw 30 moves ahead in game 1'.

So, part of the Kasparov confusion is that he was not able to
predict his opponent behaviour based on the previous game,
partly because DB changed its playing style, and partly because
of the Kasparov's own assumptions. That's exactly what he says -
'it plays this move here, and based on that I cannot beleive it
played that move there'.

Eugene

>>The other explanation, a bug, sounds not fair to the Deep Blue team.
>>
>
>Actually bugs, or general malfunction during this part of the game, is quite
>high in my list of possible explanations. There are a lot of strange things
>going on. Here's one of them (the PV for iteration 10):
>
>36. Qb6 Rab8 37. axb5 Rab8 38. Qxa6 e4 39. Bxe4 Qe5 40. Bf3 Rd8 41. Qa7 Qxc3 42.
>Bh5
>
>Question: how to explain the appearance of the move 41.Qa7 in the PV ?
>
>Amir



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