# Computer Chess Club Archives

## Messages

### Subject: Re: Proving something is better

Author: Dann Corbit

Date: 16:48:42 12/17/02

Go up one level in this thread

```On December 17, 2002 at 19:42:10, Bruce Moreland wrote:

>On December 17, 2002 at 19:10:42, Dann Corbit wrote:
>
>>I think perhaps a good measure of ability would be to take a set such as WAC and
>>normalize it with a good engine on a platform of known strength.  The time to
>>complete would be (perhaps) 5 seconds per position, and the square root of the
>>sum of the time squared would be used as a measure.
>>
>>Let's suppose that on a 1GHz machine, Crafty solves 297/300 and that the square
>>root of the sum of the time squared was 300.  If two program solve an equal
>>number of problems, then we use the time for a measure of goodness.  If not,
>>then the number of solutions will be more important.
>>Now, we will have a test that should be fairly reproducible.  Repeat this test
>>procedure for a dozen or so test sets.
>>
>>After all, when playing chess, two things are important:
>>2.  Getting it fast.
>>
>>If other programs were tested under a similar setup, we might find some
>>interesting results.  For instance, if one program averages 1/10 of a second to
>>solve problems, even though it solves the same number, it would probably
>>dominate over a program that takes 1 second on average to solve them.  Of
>>course, it might not scale cleanly to longer time controls, but it seems nobody
>>has the patience to test them like that.
>>
>>I suggest taking the square root of the sum of the squares to reduce the effect
>>of sports that are abnormal either in quickness or slowness to solve.  Then the
>>general ability will be more clearly seen.  A straight arithmetic average could
>>easily be bent by outliers.
>
>I think that this is diverting, mostly.
>
>Let's stipulate for the moment that getting more answers in less time is *proof*
>that a version is better tactically.

It is really proof that the test set of problems is solved faster.  To assume
that the program is better tactically with only one set of problems is (I think)
a serious mistake.

>The way Omid did his test, you can't tell
>the new version is better, because he didn't provide the right numbers.  We
>don't know if it got more answers in less time than the R=3 version.

We know less nodes.  So we can say:
"The new version solves this test set in less nodes."
Nothing more, nothing less.

>We have his new version, and it gets to the same depth more slowly, and finds
>more answers, than R=3.  This proves nothing.  I could make a program where the
>eval function incorporates a 2-ply search.  It would take longer to search 9
>plies, but it would get a lot more right.  This is the same result that Omid
>got.  Did he just prove that my hypothetical program is better?  Of course not.
>
>If you accept his method as proof, he did prove that VR=3 is better than R=2, I
>point out.  But he should have tackled R=3, too, if he is going to present that
>data.

No, he does not have to prove that unless he states that condition.  IOW, if he
makes a statement about the experimental outcome, he should provide data to back
it up.  If he fails to provide data, then the statement is wild extrapolation.

I don't remember if he claimed that VR=3 was better than R=3.  If he did state
that and failed to provide data, then it is an unverified assumption.

```