Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: "Percentage of fail-highs" question

Author: Gian-Carlo Pascutto

Date: 15:24:21 01/03/00

Go up one level in this thread


On January 03, 2000 at 16:52:21, Daniel Clausen wrote:

[snip]
>   #q=19291 [1%]         // #(quiescense-nodes#

Wow...does *my* chessprogram have a problem or is this very few ?

>   #fhs=27982 [55%]      // #positions where I get a fail-high (FH)
>   #fh1s=23591 [47%]     // #positions where the FH occurs after the 1st move
[..]
>As you can see, the percentage on fail-highs after the 1st move, are *far*
>away from the 90%...

23591/27982 = 84%

Not that bad...I'm getting about the same values...I don't think you
can get much higher without SEE.

>I agree that my move-ordering is not the best:
>  - Hash move
>  - Capture moves (ordered by MVV/LVA)
>  - Other moves (the first two sorted by history-value)

Add killer moves(better than history in my experience), SEE and
internal iterative deepening...this should get you above 90%. But
SEE can incur a serious speed penalty, depening on your program's
design.

>So I surely can improve a bit with a more decent move-ordering.

A bit...yes

>But my feeling is that hash moves should have the biggest influence.

Correct.

>I'm beginning to think that maybe I count them in a wrong way.

You divide the number of nodes where you fail high on the first
move by the number of nodes where you fail high. This is your
move ordering 'percentage'.

--
GCP



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.