Author: Brian Smith
Date: 08:39:27 08/10/99
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On August 10, 1999 at 03:18:43, Shep wrote: >On August 09, 1999 at 14:19:04, Brian Smith wrote: > > >>I think the Selective Search works this way: >> >>Example: Search at 4/12 ply >> This means that CM searches all possible moves for the next 4 moves (brute >>force) and then selective search (not all possible moves) to the 12th ply--4 >>brute force + 8 selective search. Of course, like any other program CM uses >>extensions. If there is a capture for example, or a mate threat, or whatever >>else extensions there are in TheKing (the extensions, of course, are pretty >>complex) then it extends the search beyond the 12th ply. > >Exactly. (But as I said, this "8 ply selective" does not necessarily mean you >have SS set to 8.) >The "x/y ply" above would be displayed as "y/z ply" by other programs. >The first number is indeed the brute force search, as can be seen by setting >SS=0 (CM would then only show "5/5", "8/8" etc.). > >I only wish CM would also show its maximum selective depth. I wonder if "Max >Depth=20" means "no lines deeper than 20 ply" or "no lines deeper than brute >force + 20 ply" (which would expand to 24 in your example) or "no lines deeper >than ordinary selective depth + 20 ply" (meaning 32 in your example)... > >--- >Shep Well, if Maximum Depth is set to 1 there are still lines with 3 moves (depth 1/1) due to the extensions. It doesn't mean "no lines deeper than 20 play" as can be seen from endgame example (near to a mate) if time is set on infinite. CM will go a lot higher than 20--I believe it goes up to 60 or something like that. "No lines deeper than brute force + 20 ply" wouldn't make sense because the Selective Search setting limits it to "Brute Force + 10 ply". The maximum search setting is nothing but the maximum of the selective search (i.e. if maximum search is set to 8 the following are possible searches: 1/8, 2/8, 3/8/, 4/8,...8/8). Even though it displays 20 as it highest depth while viewing a personality, moving the slider its furthest to the right will reveal (as you foiund out recently) "max" which doesn't mean "20" but as rather "maximum". Below is a simple example to prove that TheKing's search goes higher than 20: -- BK -- -- -- -- -- -- -- -- -- -- -- -- BP BP -- -- WQ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- (White to move) WP -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WK -- -- -- I got up to about 35/36 in this example with the default setting, but I believe I have been higher than that before. Hope that clears things up.
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