Author: Matthew Hull
Date: 20:50:27 01/13/05
Go up one level in this thread
On January 13, 2005 at 18:21:06, chandler yergin wrote:
>On January 13, 2005 at 12:46:40, Robert Hyatt wrote:
>
>>On January 12, 2005 at 20:57:40, chandler yergin wrote:
>>
>>>On January 12, 2005 at 20:33:25, Dann Corbit wrote:
>>>
>>>>On January 12, 2005 at 20:25:24, Uri Blass wrote:
>>>>
>>>>>On January 12, 2005 at 19:56:25, Dann Corbit wrote:
>>>>>
>>>>>>On January 12, 2005 at 19:37:29, Steve Maughan wrote:
>>>>>>
>>>>>>>Dann,
>>>>>>>
>>>>>>>>Things that seem impossible quickly become possible.
>>>>>>>
>>>>>>>I recon about 300 years before a computer will solve chess. This assumes
>>>>>>>
>>>>>>>1) 10^120 possible positions
>>>>>>
>>>>>>This is far, far too large. Chess positions have been encoded in 162 bits,
>>>>>>which puts an absolute upper limit at 10^58 (and it is probably much less than
>>>>>>that).
>>>>>>
>>>>>>>2) Alpha-beta cutting this down to 10^60 sensible positions
>>>>>>
>>>>>>The incorrect first assumption renders this and all following assumtions as
>>>>>>moot.
>>>>>
>>>>>The second assumption is also not correct.
>>>>>
>>>>>By the same logic alphabeta can cut less than 2^30 positions in KRB vs KR to
>>>>>2^15 positions but it does not happen and solving some KRB vs KR position with
>>>>>no KRB vs KR tablebases is not something that you need 2^15 nodes for it.
>>>>
>>>>No. The second assumption would be true if the first was true. This was
>>>>formally PROVEN by Donald Knuth. In a perfectly ordered alpha-beta solution
>>>>tree, the number of nodes is proportional to the square root of the nodes in the
>>>>full tree.
>>>>
>>>>If there were 10^120 in the full tree, then about 10^60 would be in the solution
>>>>tree.
>>>>
>>>>It can be less than that.
>>>
>>>It "Can't be LESS than that!
>>>
>>> But it cannot be more.
>>>
>>>
>>>It Certainly CAN!
>>>
>>>In any TREE.. the TREE ONLY represents "What HAS Been PLayed."
>>>REFUTE THAT!
>>>Can't HUH?
>>>
>>>Give it up!
>>
>>
>>this is going nowhere. DC is correct here, and the math is there to support
>>him. AB gives a minimal tree size with perfect ordering. If you do perfect
>>ordering, the AB tree will _not_ be larger than the usual estimate. If you use
>>hashing, it can be even smaller since you can avoid searching duplicate
>>sub-trees that normal alpha/beta would search...
>>
>>In the above context, the tree does not represent "what has been played", It
>>represents everything that has or can possibly be played in this particular
>>position and its successors.
>
>NONSENSE!
>A TREE is "ONLY" what has been Played"
GAME TREE
Definition: A tree representing contingencies in a game. Each node in a game
tree represents a possible position (e.g., possible configuration of pieces on a
chessboard) in the game, and each branching ("edge" in graph terms) represents a
possible move.
http://www.hyperdictionary.com/computing/game+tree
>Are you one of the "DUMB, DEAF, & BLIND"?
I'm guessing you posted this after looking in the mirror.
>I thought you had some Common sense!
>Guess I was Wrong!
>
>>
>>Time to move on...
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.