Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: About qsearch...

Author: Severi Salminen

Date: 08:14:19 12/30/01

Go up one level in this thread


>The first use of SEE (historically) is not to sort capture moves.
>The first use of SEE is to replace what we call now QSearch.

Ok.

>You arrive at a horizon node. Now you want an evaluation of this node. There are
>two main ways of doing this:

Ok, I didn't remember what horizon node means.

>1) you call your SEE, and it tells you how much material the side to move can
>win in this position (by doing a Static Evaluation of the possible Exchanges
>from this position). You return a score of eval+SEE (or eval-SEE depending on
>your conventions).
>
>2) you call the QSearch, which is going to try all the possible captures and
>return a minimaxed score.
>
>
>We are talking in this thread about the advantage of 1 on 2 (or vice-versa). So
>we want to compare the difference of the tree size of 1 or 2.
>
>While I understand that you want to count horizon nodes in the QSearch (after
>all each horizon node is the root of its QSearch), horizon nodes are also
>visited by the first method (SEE).
>
>So in order to compute the difference in visited nodes of the two methods, you
>need to count QSearch nodes that would not be visited by the SEE method. So you
>don't count horizon nodes (you don't count the root of the QSearches, only the
>moves or nodes which are generated BY the QSearch).

And when you (or was it Ed) said you spend 15% of nodes in QS you exclude
horizon nodes? I think my search will look a lot better with this new counting
method :) If I count the way I used to do, I have 65% of all nodes are qnodes.
I'll test what the number is if I include horizon nodes to actual nodes and not
to qnodes.

I think we should set some standards for these bloody nodes and qnodes...

Severi



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.