Author: Christophe Theron
Date: 09:42:37 12/02/98
Go up one level in this thread
On December 02, 1998 at 03:22:10, blass uri wrote:
>
>On December 02, 1998 at 01:45:10, Christophe Theron wrote:
>
>>On December 01, 1998 at 20:36:09, Kim Hvarre wrote:
>>
>>>Hello Ed,
>>>
>>>Exiting project You and Chistophe have going with The Tiger. In this relation
>>>just one question, quoting Your homepage:
>>>
>>>"One of CHESS-TIGER's search algorithms has been implemented in REBEL and is
>>>further improved by Ed Schröder. The CHESS-TIGER idea plus Ed's own improvements
>>>have speed up REBEL with a factor of 2-3. The first results are very promising.
>>>At the playing level of 1:00 per move REBEL scores 47½-31½ against various
>>>strong computer opponents.
>>>
>>>For the moment the conclusion is Christophe's idea has given REBEL an elo jump
>>>of at least 30 elo points but more likely the gain in playing strength is 50 elo
>>>points or even more. The basic idea is im-plemented in the third party engines
>>>of:"
>>>
>>>The question: The large jump in speed is this on behalf of something else
>>>(knowledge, whatever) or is it just a "simple trick"/algoritme/?, You and
>>>perhaps others have overseen?
>>>If so, it's a rather amusing and a nice perspective in respect to the promising
>>>future of search.
>>>
>>>Regards,
>>>
>>>kim
>>
>>Maybe Ed will answer too, but I can give you some info.
>>
>>As Ed and I have suspected right from the begining of the project, Rebel and
>>Tiger are very very different programs.
>>
>>It appears that we use different algorithms to achieve a relatively close level
>>of play.
>>
>>Some of these algorithms are incompatible with each other by nature. Maybe we
>>will be able to get something by exchanging them, but it is not sure.
>>
>>But there are other algorithms that are compatible in both programs. And this is
>>very interesting. Ed has found ideas that I have not found, and the opposite is
>>true also. In the case Ed describes, one of Tiger's selection algorithms that
>>did not exist in Rebel has been successfully implemented in Rebel.
>
>Does this selection algorithm speeds up Rebel by a constant factor or maybe the
>factor is a function of the time per move?
>
>>
>>This algorithm is not really a programmer's trick. It is an idea taking
>>advantage of the nature of the chess game. I cannot say more, but I would rather
>>describe this as being knowledge, because it would certainly not work with other
>>games.
>
>Does it work in all the cases in chess or maybe it only works practically in
>99.99% of the cases.
Rebel scores much better in matches. I would say it works much more often than
it fails.
>I know that there are positions that Fritz5 can never solve because of the null
>move(it does not analyze moves with no threat in the middle game).
>
>These positions are rare so practically it is not a problem but it can be a
>problem in solving studies
>
>Are there problems with some rare positions with the faster Rebel?
Ed should answer this.
I my case, the new algorithm does not produce new "holes". In the worst case a
combinational key move can be found a little later, and that's all. In most
positions it is a clear win.
Christophe
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