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Subject: Re: DEEP BLUES AVERAGE PLY?

Author: Uri Blass

Date: 23:13:49 08/21/02

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On August 21, 2002 at 22:32:03, Robert Hyatt wrote:

>On August 21, 2002 at 19:14:17, Vincent Diepeveen wrote:
>
>>On August 21, 2002 at 17:52:53, Robert Hyatt wrote:
>>
>>>On August 21, 2002 at 17:31:53, Uri Blass wrote:
>>>
>>>>On August 21, 2002 at 17:21:08, Robert Hyatt wrote:
>>>>
>>>>>On August 21, 2002 at 14:48:04, Vincent Diepeveen wrote:
>>>>>
>>>>>>On August 21, 2002 at 14:42:49, Robert Hyatt wrote:
>>>>>>
>>>>>>Bob if you don't read what they write,
>>>>>>then please show us you can do math.
>>>>>>
>>>>>>Please quote what is the theoretic number to search FULLWIDTH without
>>>>>>hashtables OR killermoves and WITH singular extensions a treesize
>>>>>>of 18 ply..
>>>>>>
>>>>>
>>>>>First, they don't claim to do "fullwidth" in the hardware.
>>>>
>>>>The 12.2 is software+hardware depth.
>>>>It is very clear from their paper.
>>>>
>>>>see page 13 table 2
>>>>
>>>>iteration 12
>>>>minimum software depth 8
>>>>
>>>>The explanation say that is it about the position before white's move
>>>>in game 2 against kasparov.
>>>>
>>>>Uri
>>>
>>>
>>>I don't begin to know how to interpret those numbers in light of the email
>>>I have received from the DB group about the 12(6) issue.  IE do you assume
>>
>>We talk about an email around the year 2000 (in 1999 you still said
>>12 ply) from a dude called Campbell , not the programmer of the thing
>>Hsu. He probably referred to 'average' search depth. They have a big
>>table later in the paper *average* search depth.
>
>
>First, it wasn't from Murray, it was from Andrew, a different member of
>the team.  You obviously don't know any of them so I won't go farther
>there.  Second, if you recall the email, Andrew _specifically_ said he
>talked to CB (Crazy Bird, AKA Hsu) to verify that it had not been changed
>in meaning.
>
>What more can I say?
>
>
>
>
>>
>>Suggesting that deep blue 2 which was only slightly faster than deep blue 1
>>(no more than a factor 2) getting suddenly 6 plies extra is not possible.
>
>I don't know what you mean.  I personally watched deep thought search 10-11
>plies deep in the middlegame in 1989-1994 games at ACM and WCCC events.  I
>_saw_ that.  Deep Though was credited with roughly 1-2M nodes per second
>by Hsu and team.  DB was clearly a hundred times faster.  Which should
>certainly produce 5 more plies at their 4.0 branching factor...

4^5=1024 4^4=256

so even with branching factor of 4 and being 100 times faster
they can see only less than 4 more plies.

If you consider the fact that the real branching factor was more than
4 and they were less than 100 times faster(the 200M nodes by IBM
was misleading and the effective speed was clearly smaller)
then you get less than 3 plies.

If you consider the fact that deeper blue di more extensions than
deep thought then you can get less than 2 plies.

Uri



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