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Subject: Re: DT and DB (prototype) vs Computers

Author: Ernst A. Heinz

Date: 10:09:52 01/25/00

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On January 24, 2000 at 23:10:12, Robert Hyatt wrote:
>
>On January 24, 2000 at 16:02:48, Ernst A. Heinz wrote:
>
>>>Sure, but it did full singular extensions and the rest of the things we were
>>>all doing then.
>>
>>I do not remember having heard or read Hans Berliner talk/publish
>>about singular extensions in "Hitech".
>>
>>Please enlighten me where you got that information from.
>
>From sitting across the board from them at an ACM event.  Murray was at
>the table as well, and we had a long discussion about singular extensions
>after deep though was using them.  They implemented them in HiTech very
>quickly after the idea was published...  That was the reason I added them
>to Cray Blitz...  I had used this sort of idea a long while back, at the
>suggestion of someone whose name I don't recall.  It didn't work well in
>1978 and I removed them from the program just prior to the ACM event that
>year, because it costs us well over one ply, and going from 5 to 4 was a
>killer.
>
>They were using them in at least the last few ACM events... I don't recall
>when they added them.  You could probably ask Murray since he probably wrote
>the code for adding them to HiTech.  They were also using Ken's databases in
>the search (not only at the root) way back then too...

Interesting.

Hans Berliner visited us in Karlsruhe in summer 1996 for
almost one week and I also had considerable email contact
with him about "Hitech".

He never said anything about singular extensions then.

Moreover, we let the old "DarkThought WMCC'95" running on
a slow 275MHz Alpha-21064a (ca. 30K nps) play some test
games against "Hitech B*". This old and slow version of
"DarkThought" won all the games although Berliner claimed
that "Hitech B*" was even stronger than the normal "Hitech"
(and yes, in the endgame, Berliner manually switched to the
normal "Hitech" during these games).

Of course, we did not play enough games to gain any
statistically significant insight into the relative playing
strengths of both programs. But I was extremely disappointed
by the performance of "Hitech" at that time -- especially
because it was roughly 5x faster in terms of nodes searched
per second.

=Ernst=



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