Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Mathematical impossibilities regarding Deep Blue statements by Bob

Author: Uri Blass

Date: 13:19:51 01/31/02

Go up one level in this thread


On January 31, 2002 at 14:36:04, Dann Corbit wrote:

>On January 31, 2002 at 14:31:38, David Rasmussen wrote:
>
>>On January 31, 2002 at 13:13:57, Dann Corbit wrote:
>>
>>>On January 31, 2002 at 06:58:28, David Rasmussen wrote:
>>>[snip]
>>>>>Just like "ply" means 20 different things to 20 different programmers.  Even
>>>>>"nodes" does not always mean the same thing.
>>>>>
>>>>
>>>>Agree with you on nodes, but ply? Ply is pretty well defined, I think.
>>>
>>>For sure it is not.  In fact, even when we agree, we disagree.  Every single
>>>chess program will have a tree of a different shape.  So even when we count
>>>plies the same way, the actual search can be incredibly different (with the
>>>number of nodes visited differing by several orders of magnitude).  Compare, for
>>>instance, Mchess with Goliath.
>>>
>>>Junior [for instance] does not count plies the same way as other programs.
>>>
>>>Ply is ill defined.  In fact, I think it is actually impossible to define it
>>>accuracy, except in the brute force sense.  And absolutely nobody exhausts a ply
>>>when doing chess games with an engine.
>>>[snip]
>>
>>That is bull. A ply is a half move and that is that. What you are talking about
>>is: what does it mean when we say a program searches 8 ply? Of course if that is
>>the question, the answers are as many as there are programs. But in this thread
>>we are talking about a full width alpha-beta tree (at least, since DB had
>>singular extensions, which requires extra searches), of some fixed depth search
>>in a given program (that is, move ordering and evaluation forms the tree).
>
>I suggest that you lookup with the CCC search engine the dozens of posts that
>shot *ME* down when I tried to insist that a ply is a ply is a ply.
>
>The thorough and convincing arguements against it showed that I was clearly
>wrong.
>
>As you are clearly, unmistakeably, and totally wrong right now.

He is not wrong if we talk about full width alpha beta.

Uri



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.