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Subject: APHID , advances in ICCA #8

Author: Vincent Diepeveen

Date: 06:10:02 09/18/01

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On September 17, 2001 at 12:00:45, Gian-Carlo Pascutto wrote:

Hello now that i saw this link and downloaded the source i
realized this was also published in advances in ICCA volume 8,
of course i got this book and first removed some dust from it,
after which i opened it and saw at page 71 claimed next
by M. Brockington and J. Schaeffer

"... Although most parallel alfabeta-programs take months to develop,
the game-independant library allows users to integrate parallellism
into their application with only a few hours of work"

[cough]

Well if no one here manages to do that, who am i to say that the
remainder of this algorithm is worth trying?

For sure there is a speedup problem.

But there is more. It's a complete different algorithm than YBW.

Which means that APHID already says who has to search what before relevance
of parallel splitting has been indicated. Considering that nowadays we
use nullmove bigtime, this makes APHID completely outdated, because
it in short doesn't wait at all!

First few pages it says that a major problem with YBW is the idle time.

This refers to the fact that YBW for each node needs a result for the
first move first before splitting other moves. Now this is of course very
true, but this directly also shows that APHIDs branching factor is by
definition bigger than algorithms which use YBW.

Back in 1996 for example TheTurk which used APHID searched 2500 nodes
a second. I don't need to mention that for nowadays networks capable
of searching millions of nodes a second, that branching factor is a bigger
problem than it used to be in 1997.

Note that Deep Blue used seemingly a similar approach to APHID, which
considering its search depth was no problem to use of course.

>On September 17, 2001 at 11:54:35, Vincent Diepeveen wrote:
>>On September 17, 2001 at 07:10:46, Gian-Carlo Pascutto wrote:
>>
>>Well show me the code and i can run it here at my 100mbit
>>network then!
>
>ftp://ftp.cs.ualberta.ca/pub/games/aphid
>
>APHID libs, crafty version for them
>
>You need PVM (Parallel Virtual Machine, standard message-passing
>lib), and probably a quick look at some of their docs how
>to set up the config files.
>
>You can get the papers/thesis and all from
>
>http://www.cs.ualberta.ca/~games/aphid/index.html
>
>--
>GCP



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