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Subject: Re: CM8k (& Rebel) Personality (Selectivity) Question

Author: Brian Kostick

Date: 20:22:00 04/08/01

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On April 08, 2001 at 14:53:15, John Merlino wrote:

>On April 08, 2001 at 04:36:03, Brian Kostick wrote:
>
>>snips:
>>Tina wrote:
>>>>The following Statements are REASONABLY correct:
>>>>CM8k:   Depth  6/12   6ply brute force, 12ply "selective" (SS set at 6).
>>or
>>Uli wrote:
>>>I believe that 6/12 in CM6k and probably also in CM8k means the following:
>>>1)first 6 plies brute force without null move pruning.
>>>2)next 6 plies brute force with null move pruning
>>>3)big extensions
>>
>>
>>Tina and Uri,
>>
>>   You both note that there is a difference of 6. My point was that at ANY time
>>beyond the first 30 seconds or so you can take the 'Depth' reading from
>>Chessmaster 8000 thinking lines. Now subtract the two numbers and change sign.
>>The result always equals the Selective Search setting. If you change the
>>Selective Search setting then you change the ratio beween the two Depth numbers.
>>
>>  I appreciate both of your commentary, despite terminology differences, it
>>means more to me than the description given in the owners manual. Regards, BK
>
>This is not always true. As more and more material is taken off the board, the
>difference between X and Y in the X/Y depth value becomes smaller. So, in the
>opening, you might get "6/12". In the midgame, with the queens and a minor piece
>and a few pawns off, you might see "7/12" or "8/12". In the endgame, with only a
>few pawns and one piece, you will likely see "11/12". This is ALL with a
>selective search setting of 6.
>
>jm

  I can deal with that, I guess appearances are deceiving. Now I'm back to the
written description of Selective Search the owners manual provides.

  "It sets the number of plies (from 1 to 12) that the personality looks at
before making its next move. Unless told to do otherwise, the personality
considers all possible plies (which can be infinite in number) before making
it's next move."

  This is confusing for me. It sounds more like MSD and time control must also
come into play.  Anyway, I can test settings and zero in on those that seems to
suit my purpose. I DID know not to post to a controversial 'settings' topic and
did so anyway, my mistake.  Regards, BK




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