From PsychoWiki

Note: stats.pl starts with a lower-case letter "s", not capital like the title of this page suggests.

What does "stats.pl" do?

"stats.pl" is the heart of PsychoStats. It's responsible for just about everything related to collecting and parsing logs, calculating awards, scanning for clans and removing old/stale statistics.

Most users will want to schedule the "stats.pl" to run automatically every X number of minutes per day. This is how PsychoStats continually updates the stats. It does not have it's own daemon built in to do it on it's own.