Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: alpha-beta is silly?

Author: Komputer Korner

Date: 13:48:17 06/02/98

Go up one level in this thread


On June 02, 1998 at 11:22:58, blass uri wrote:

>
>On June 02, 1998 at 10:04:31, Robert Hyatt wrote:
>
>>On June 02, 1998 at 09:05:17, blass uri wrote:
>>
>>>
>>>On June 02, 1998 at 05:03:32, Inmann Werner wrote:
>>>
>>>>Alpha - Beta is silly?
>>>
>>>I am sure about it
>>>grandmasters are better than computers and do not use the
>>>Alpha- Beta
>>>It is hard to find a good algoritham
>>>and the target should be to find less silly algoritham
>>>>
>>>>Yesterday, I tried the LCTII Test Suite, position LCTFIN01. I was
>>>>amazed, that INMICHESS (my program) needed  depth 9 to solve  the
>>>>position. (running pawn)
>>>>
>>>>
>>>>The position: Kc2/Pf2/kc4/Pg4/Pf5/Ph6/pb7/pf7/pg7/ph6
>>>>Best Moves: 1.f6  2.gxf6 3.f4 4.b5 5.g5 6.fxg5 7.fxg5 8.hxg5 9.g6
>>>>....->Queen
>>>
>>>I did not understand the position
>>>white and black cannot have the same pawn at h6
>>>
>>>Uri
>>
>>
>>actually, I've been playing chess for 40 years now, and *I* use alpha/
>>beta when I play.  IE once I analyze my first candidate, and then start
>>on the second candidate I often quit quite quickly when I see something
>>bad, without really analyzing to see "how" bad.  So it is not that
>>"foreign" a concept to chessplayers, they just don't realize they are
>>doing the same thing...
>
>good players do also other things
>
>1)they know they should analyze a move
>that they think it leads to an unclear position
>(for example if they think to sacrifice material for initiative)
>
>2) if they do not see a forced line
>(they have no time to check all the possibilities)
>they can use a statistics to decide
>if they see in a position  that every line they analyze
>leads to their win when they play against themselves
>they decide to go to the position.
>
>3)good players see there are moves that should not be analyzed
>when in the alpha-beta we analyze every legal move to prove it is not
>the
>best.
>Uri


It is not a requirement of alpha beta that every move be analyzed. Alpha
beta is actually a rigorous mathematically sound rule that certain moves
do not have to be analyzed because mathematically they have been shown
to be inferior without having to search their move trees.  You are
confusing alpha beta and intuition. They ARE NOT exact opposites of each
other despite what you think.
Chess players are intuitive even Kasparov. This is necessary because of
poor human calculation speed. Chess computer programs can be either
selective search or full width. Either way they all use alpha beta which
is really only a mathematically pruned minimax. Even humans use alpha
beta. Your argument is with intuition, knowledge and full width
searching. What you call knowledge is stuff that hasn't been programmed
into chess computers yet. It is very difficult to teach a robot to pick
up a glass off of a table. You accomplish that task very easily. The
same thing goes for teaching chess knowledge to a program. Don't confuse
a mathematical principle like Alpha beta with chess knowledge. I think
it is time for Bob Hyatt's yearly alpha beta lesson because it is clear
you do not understand what alpha beta is.



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.