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Subject: Re: positions when deep thought blundered

Author: Uri Blass

Date: 04:57:50 08/21/02

Go up one level in this thread


On August 21, 2002 at 06:33:05, Gordon Rattray wrote:

>On August 20, 2002 at 21:48:59, Robert Hyatt wrote:
>
>>On August 20, 2002 at 18:42:07, Uri Blass wrote:
>>
>>>On August 20, 2002 at 17:49:34, Robert Hyatt wrote:
>>>
>>>>On August 20, 2002 at 17:02:52, Uri Blass wrote:
>>>>
>>>>>I include only gam,es from 1993
>>>>>
>>>>>Deep Blue - Hamann,S
>>>>>5R2/r5pp/3N2k1/3Ppp2/2P5/p7/P5PP/2n3K1 w - - 0 38 bm Nb5
>>>>
>>>>What did DT play here?  I only find Nb5 and I find it instantly and stick
>>>>with it...  score =+1.5 so apparently DT was winning here.  Did it lose by
>>>>playing something else???
>>>
>>>Yes it lost by Rxf5
>>>
>>>This is a typical computer move because it wins a pawn if you do not search deep
>>>enough when Nb5 does not win a pawn(unless you search very deep and I am sure
>>>that your +1.5 is based on poasitional factors).
>>
>>The problem here is that we don't know what happened in the game.  IE deep
>>thought _always_ played over a network connection.  In the late 80's and
>>early 90's the net was not as accessible and reliable as it is today, and it
>>is certainly possible that they lost the connection, didn't know it, and
>>after they found out, they had to move quickly.  Happened to me and Cray Blitz
>>many times.  Happened to deep thought against Fritz in Hong Kong 1995 in
>>fact...
>
>
>I think I remember reading about this in a chess magazine (Chess Monthly, UK) at
>the time.  DT played Rxf5 after about 30 seconds.  Later it was discovered that
>a 42 second search would have found Nb5.  Even if my figures aren't exact, I'm
>pretty sure they're close (I can dig it out if necessary).  I don't know what
>the time control was for the game.
>
>Gordon
>
>
>[snip]

I read about it in the past and if I remember correctly Deep thought needed 48
seconds to find Nb5 but in the game(1 hour per game) it used only 42 seconds.

The point is that most of the top programs of today can see it faster(some
programs like crafty even see it immediately).

I looked only in few games from 1993 and I do not expect to see the same number
of mistakes with top programs of today.

If you look in many games you can find also mistakes of tiger that other
programs can avoid but I believe that it is possible to prove that the number of
tactical mistakes that deep thought did in games is simply bigger.

I did not have the time to check it so I may be wrong but the only way to
convince me is to show data and my impression based on looking at games is that
deep thought blundered more often.

Uri



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