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Subject: Re: Live chat with Feng-Hsiung Hsu (of Deep Blue fame) on ICC

Author: Robert Hyatt

Date: 08:51:13 10/11/02

Go up one level in this thread


On October 11, 2002 at 07:43:40, Uri Blass wrote:

>On October 11, 2002 at 07:12:34, Vincent Diepeveen wrote:
>
>>On October 11, 2002 at 04:08:49, Uri Blass wrote:
>>
>>Isn't his article clear enough yet?
>
>Bob Hyatt still claims that it was 12 plies software and 6 plies hardware
>so I prefer to hear an answer directly from Hsu.

I agree.  But _I_ don't claiam _anything_ except that members of the DB team
specifically told me that 12(6) means 12 plies in hardware, 6 in software.  I
even posted the excerpt from the email that specifically said this...

That is _all_ I have said about it...




>
>>
>>reporting a 12.2 average search depth fullwidth.
>>I guess you never searched with a decent program fullwidth
>>with extensions. If you did, you would understand that
>>getting 12.2 ply fullwidth with loads of extensions is already nearly
>>impossible. Every extended line is searched to the full depth,
>>no pruning happens!
>
>I agree that 12.2 plies with a lot of extensions and no pruning is impossible
>for normal programs and also is impossible for deep blue in case that
>there were real 6 more plies in the hardware.
>
>The only case when it may be possible is if the 6 more plies in the hardware are
>real selective search and it means more pruning than null move with R=3 and in
>this case the 6 plies in the hardware may be eqvivalent to only 2 plies in
>software because of big probability to miss things.
>
>>
>>The interesting 2 questions are
>>  a) did DB use 'no-progress pruning' in SOFTWARE (we know
>>     already it used it in hardware).
>
>They explained in the article that they did not want to take risks of missing
>something in the first plies so it is clear that they did no pruning in the
>first 12 plies.
>
>If they did some pruning in the software it is clearly after it.
>
>I do not know what is exactly no progress pruning.
>Is there a difference between it and null move pruning?
>
>Is no progress pruning more aggresive than null move pruning?
>
>Uri



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