TPM,
The Wall Street Journal has a great section called "The Count". They do all sorts of analyses on all aspects of professional sports.
Some of it can be accessed for free on the web. I read it from time to time as it is a great source of statistical analyses.
Recently I read an article on the "demographic" history of MLB players. It was really interesting. They went all the way back to the 1940's.
Alot of interesting stuff.