Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: The Cause of controversy & misunderstanding

Author: chandler yergin

Date: 08:38:09 10/21/05

Go up one level in this thread


On October 21, 2005 at 02:56:24, Terry McCracken wrote:

>You are aware that ChessBase acknowledges these bugs and has made a patch?
>
>Terry

There are no Bugs in any Engine!
The Engine does nothing.
The Algorithm does everything!

http://www.seanet.com/~brucemo/topics/minmax.htm

"Let's say that at the root position (the position on the board now), it's
White's turn to move.  The Max function is called, and all of White's legal
moves are generated.  In each resulting position, the "Min" function is called.
The "Min" function scores the position and returns a value.  Since it is White
to move, and White wants a more positive score if possible, the move with the
largest score is selected as best, and the value of this move is returned.

The "Min" function works in reverse.  The "Min" function is called when it's
Black's turn to move, and black wants a more negative score, so the move with
the most negative score is selected.

These functions are dual recursive, meaning that they call each other until the
desired search depth is reached.  When the functions "bottom out", they return
the result of the "Evaluate" function.

If you call "MinMax" with a depth value of 1, essentially all that happens is
that the "Evaluate" function is called after each legal move, and the position
that results in the "best" value for the side to move is selected.  If depth is
greater than one, the other side gets a chance to respond, and chose its best
move.

The above shouldn't be hard to understand,"

To say there is a Bug in the Engine is just not correct!
To say that the Algorithm is biased.. does not work for some positions
is not correct.
If it did, it would not work for any position, and would be disfunctional.




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.