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Subject: Re: LCT II Fin4, Deep Thought, and Deep Blue (was Re: LCT II results...)

Author: Robert Hyatt

Date: 19:55:57 01/07/98

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On January 07, 1998 at 14:40:27, Willie Wood wrote:

>you wrote >>
>When I worked with the 6502 processor I hardly did any extensions as
>with the slow 4-5 Mhz this was quite dangerous. I tried more extensions
>in the Milano program which should have been the main improvement over
>the Polgar. It didn't work. 500-600 NPS doesn't justify that.
>I didn't know you did those programs.  Amazing what one learns...  I
>wrote a 6502 chess program in 1978, and I believe the processor ran at 1
>mhz. You must have been working with the hotrod 6502. :)
>btw, you might be interested to know that, on my powerbook 5300ce, which
>is a ppc 603e running at 117 mhz, Hiarcs 6 (PPC) runs at 328 nps.  This
>is an average taken from an epd test suite done for the upcoming KKKup.
>This result has been verified on another 5300.  But the point is, it
>plays a darned good game nonetheless, and I would venture to say the
>extensions are pretty extensive.

I think Ed was simply relating something we've all encountered.  Things
that work poorly at slow speeds sometime work well at faster speed.  IE
imagine a program that can only search 5 plies deep.  And you find some
neat extension idea, but while it does extend in some useful cases, it
drops you to 4 plies everywhere else.  Does it pay off?  probably not,
because the difference between a 4 ply and a 5 ply program is much more
noticable than if this program started at 10 plies and had to drop back
to only 9...

I tried singular extensions in 1978 and it dropped me from 5 back to 4,
and I decided (eventually) that it was no good.  Hsu tried it with much
faster hardware and it worked.  It even seems to work well for him at
100K nps based on the match he ran, which has convinced me to give this
another try later on...

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