Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: SEE for forward pruning in Q. Search and nullmove cooking problems

Author: Dave Gomboc

Date: 12:10:40 08/12/99

Go up one level in this thread


On August 12, 1999 at 08:32:02, Vincent Diepeveen wrote:

>On August 12, 1999 at 01:33:35, Dave Gomboc wrote:
>
>>On August 12, 1999 at 01:10:14, blass uri wrote:
>>
>>>This example shows that the null move is not a very good idea.
>>>If you need more 3*2=6 plies to see the right move and there is no
>>>zunzwnag(playing no move cannot help black) then you are not close to see
>>>everything to depth n-r with null move.
>>>
>>>I thought depth n when you use null move with R=2 means that except for
>>>zunzwangs you analyse everything to depth n-2 and I see that it is not the case.
>>>
>>>Uri
>>
>>Well, null-move is as you described, but what is shown above is "recursive
>>null-move", which seems to be pretty popular, and some people abbreviate
>>this as simply "null-move".  It is the sort of search algorithm that gives
>>people a happy feeling inside about how deep they are searching, but leaves
>>holes for programs like DB to drive a truck through.  Of course, Bob has pointed
>>this out more than once before.  Consider how much is being chopped out of some
>>13 ply search, and you might agree that Bob isn't just being stubborn: there's
>>actually quite a big difference in coverage.
>>
>>Of course, those who use recursive null-move are making the reasonable gamble
>>that the extra coverage isn't beneficial at their search speeds.
>>
>>Dave
>
>Now this is pure BS. Even at 5 0 Deep blue gets kicked silly by a laptop.

Your response is the "pure BS".  It doesn't even address the main part of my
post, and what it does say is factually incorrect.

Dave



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.