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Subject: Re: Nodes per second

Author: Roland Pfister

Date: 02:40:01 04/01/98

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On April 01, 1998 at 03:21:58, Andreas De Troy wrote:

>
>I am working on My First ChessProgram and I wonder how you people count
>these nps (nodes per second). I see that Nimzo98 claims 200 000 nps on a
>Pentium 200 and when I compare this to *my* current program I cannot
>imagine how I could ever reach, say, half of this number. I got
>typically between 45 000 and 70 000 nps with material evaluation only.
>
>So how do you count this? I saw in Crafty the "nodes++"-statement at the
>beginning of the ab-search and the q-search, and that's how I count too.

That is ok. Most of us do it this way.

>But maybe you should count the number of generated moves instead? (The
>number would be much higher then.)
>
If you like it :-)

>And a few days ago I saw in a message from KK that hashing influenced
>this number too so my second question is: are the hits counted, or
>aren't they?
>

I don't extra count it, it is just like a repetition or mate.

things that affect nodes per second:

alpha-beta ( if you use pure minmax your nps will grow! )
hashing ( if you don't do hashing your nps will grow )
good move ordering ( if you have bad ordering or none, your nps will
grow)

nps are only interesting, if you optimize your program and the node
count
for one particular position does not change but the time to get these
nodes becomes bigger or smaller.

if you change your algorithm and thereby change the node count, nps does
not
say much.

most important are depth reached and solution times of tests. if you
solve
more positions than before nobody will care about your nps.

hope that helps
Roland



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