# Computer Chess Club Archives

## Messages

### Subject: Re: A question about statistics...

Author: Mike Byrne

Date: 10:07:30 01/04/04

Go up one level in this thread

```On January 04, 2004 at 13:03:04, Roger Brown wrote:

>>When you play 100 games, the confidence level will be near 95% +/- 60 points.
>>So you end up with a difference that is greater than 120 points you say with 95%
>>confidence that the higher rated program is better than the lower rated program.
>> So there would be a  1 out of 20 chance that your test results are not correct.
>> If they are rated less than  120 points apart, statically, you can make a claim
>>either way, you need more games.  The closer the rating is , the more games you
>>need to achive a 95% confidence level,
>
>
>
>So it is a hundred games that you suggest.  Two hundred should be even better
>then.
>

Statistically, the more games the better - yes - your confidence level increases
with more games at a give +/- range.   Or you can decerease the +/- range and
keep your confidence level the same - either way - more games make it better.

>
>
>>
>>Statistically, the 100 games does have NOT to be against the same engine,,  You
>>can design a tournament with 11 engines, have them play round robin with rounds
>>(10 cycles) - and you confidence level for the ratings relelative to each is
>>just as valid as single 100 game match.  Alternativley, you can play 100 rounds
>>with 101 engines, they each play one game with each other - statisically it is
>>the same.  The key is simply 100 games.  Think about human ratings, you do not
>>play 100 games against the same player, you might play 100 games against 90
>>players - statistically it does not matter.
>
>
>
>Agreed but, *ahem* I do not have a sufficient number of engines to play 100
>
>I want to use engines near the top - for reasons of development, stability of
>use, substantial debugging and testing.  In short engines like Crafty, Yace and
>Little Goliath which are featured in several tournaments and can be used with a
>robust, automatic and computer friendly (memory, cpu usage etc.) gui like
>Winboard.
>
>
>I want no issues with draw claims and the like....
>
>
>:-)
>
>
>Thanks for the feedback - and for the modified Crafties!
>
>
>Later.

```