Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Crafty Book Implementation

Author: Robert Hyatt

Date: 17:48:19 06/11/01

Go up one level in this thread


On June 11, 2001 at 14:17:37, David Rasmussen wrote:

>Am I an idiot, or does that Crafty book scheme miss some transpositions, because
>of it's clustering system? Wait, those two statements aren't mutually
>exclusive...
>
>When some of the upper bits of the book hashkey, is from the parent position,
>doesn't that mean that if I'm in an unknown position, that can make a move that
>transposes into a book position, it won't, because the upper bits will only
>match the actual parent position(s) from when the book was created?
>
>I'm having an idea of another book implementation that I think is quite smart,
>but I won't reveal anything yet, primarily because I don't know if it works in
>practice, secondarily because it might not be a new idea, tertiarily because it
>might not be a smart idea at all :)


I _intentionally_ want to miss those transpositions.  One classic:

1. e4 e5 Nf3 a6 Bb5.  Do you _really_ want to transpose back into the book
and play Nc6?  Or do you want to rip the bishop and be a piece up in a won
game?

:)

My thinking when I did this scheme was "Crafty will probably play Nc6 if it
is reasonable, and _then_ we will transpose back into book after white plays
Ba4, because that is a normal position.  But the position given above is
"not normal" and I won't try to transpose.

It has happened in _real_ games in the past.  But it won't happen to me
here. :)



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.