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Subject: Re: Speed is the issue ... when?

Author: Robert Hyatt

Date: 19:08:33 01/31/04

Go up one level in this thread


On January 31, 2004 at 21:37:29, J. Wesley Cleveland wrote:

>On January 30, 2004 at 14:37:45, Robert Hyatt wrote:
>
>>On January 30, 2004 at 13:24:25, J. Wesley Cleveland wrote:
>>
>>>On January 30, 2004 at 09:45:23, Robert Hyatt wrote:
>>>
>>>>On January 30, 2004 at 02:48:52, GuyHaworth wrote:
>>>>
>>>>>
>>>>>Speed only becomes an issue when a specific endgame becomes 'relevant'.
>>>>>
>>>>>Longer term, it would be good to have more dynamic storage schemes which only
>>>>>promote EGTs to hard disc 'Just In Time' before they're needed.
>>>>>
>>>>>In round figures, I estimate 1.5TBytes for the 3-to-6-man DTM EGTs, but only
>>>>>0.6TBytes for the DTZ and EdZ50Z EGTs (from which the DTZ50 EGTs can be
>>>>>derived).
>>>>>
>>>>>In either case, I anticipate some robotic DVD-handler would be useful.
>>>>>
>>>>>g
>>>>
>>>>
>>>>The problem is, what happens on (say) a KRPP vs KR.  Potentially you will need
>>>>KR** vs KR for all the promotions.  When you reach that position, your search
>>>>will simply end, because there's no way you will copy all the KR**KR files from
>>>>DVD to the hard disk while a search is in progress.
>>>
>>>You won't need KR** vs KR until the root position is KRPP vs KR. Since your
>>>"searches" will then be only 1 ply, there may well be time.
>>
>>
>>What do you do with KRPP vs KR positions deep in the tree where you need to
>>promote?
>
>I take the exact value from the KRPP vs KR table and prune. You only need
>the KR** vs KR tables if you promote with a capture.

How can you do that?  How do you know the promoted position is a win or a draw
(or even a loss) even though the previous un-promoted position was a win or
draw?


>
>And you can't since you don't have the table?  That's the place where
>>tables help, in the search.  _not_ at the root.  By the time you reach the
>>position OTB it is already won lost or drawn.  In the search, you can control
>>where you reach the table position and choose winning over drawing...



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