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Subject: Re: Which Algorithm is considered the best ?

Author: Andrew Williams

Date: 13:37:42 08/09/00

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On August 09, 2000 at 16:10:50, Christophe Theron wrote:

>On August 09, 2000 at 05:31:52, Andrew Williams wrote:
>
>>On August 08, 2000 at 16:00:32, Christophe Theron wrote:
>>
>>>On August 07, 2000 at 05:58:44, Andrew Williams wrote:
>>>
>>>>On August 06, 2000 at 20:10:49, Vincent Diepeveen wrote:
>>>>
>>>>>On August 06, 2000 at 19:17:18, Tom Kerrigan wrote:
>>>>>
>>>>>>On August 06, 2000 at 16:37:24, Vincent Diepeveen wrote:
>>>>>>
>>>>>>>On August 06, 2000 at 12:45:11, Dan Andersson wrote:
>>>>>>>
>>>>>>>>Vincent has had this idea of MTD and never managed/bothered to defend it. I
>>>>>>>>believe it to be an unsupported opinion.
>>>>>>>
>>>>>>>No commercial program uses MTD. End of proof man.
>>>>>>
>>>>>>I thought the MP version of Fritz does.
>>>>>>
>>>>>>-Tom
>>>>>
>>>>>I never saw any MP version of Fritz in the shops so far,
>>>>>perhaps someone is gonna state soon that DB used MTD too.
>>>>
>>>>Oddly enough, this seems to be what Hsu says in his IEEE Micro article.
>>>>Unfortunately, he doesn't say quite enough to be clear:
>>>>
>>>>	"The search control does not really implement the regular
>>>>	alpha-beta search algorithm [Ref: Knuth & Moore 1975]. Rather,
>>>>	it implements a minimum-window alpha-beta search algorithm
>>>>	[Ref: Pearl 1984]"
>>>
>>>
>>>
>>>The reference "Pearl 1984" clearly indicates that they are using PVS/Negascout.
>>>
>>>    Christophe
>>>
>>
>>I'm not certain that this is true. This is a reference to: "Heuristics :
>>intelligent search strategies for computer problem solving". Addison-Wesley,
>>1984. I'm pretty sure that this book is where he first talked about the use
>>of MT (Memory Test) as a way investigating the performance characteristics of
>>alpha-beta searches.
>>
>>Andrew
>
>
>
>I have this book right in front of me (actually the french translation of it).
>
>In this book, Pearl talks about SCOUT (which is also called NegaScout or PVS),
>and about SSS*.
>
>SSS* is not a practical choice, as you need to store the entire search tree in
>memory.
>
>MTD(f) did not exist at the time the book has been written.
>
>So the only choice left is SCOUT (NegaScout/PVS).
>
>Maybe you are mixing SCOUT and "Memory Test" because the heart of the SCOUT
>algorithm is a procedure called "TEST". But TEST is actually just a null-window
>search in this case.
>
>
>
>    Christophe

OK. Thanks for this. I didn't have time to grab the book from the library.
I've just looked at Aske Plaat's thesis and it looks like the M in MT was
coined by him, not Pearl. Clearly I'm mixing up my sources.

Cheers

Andrew



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