Raw Baseball Data

Thanks to Nathan Yau at FlowingData, I found a link to a site with raw baseball data and stats at Baseball-Databank.org. The files come in csv or mySQL format. If you're not running a mySQL database, the csv files can be easily imported into Excel using the Data-Import External Data menu.

There was an article yesterday by Justin Wolfers on the Freakonomics column/blog at the NY Times which analyzed Roger Clemens's performance against the performance of other pitchers with a long history. The data seemed to indicate that while most pitchers' performance went down over time, Clemens's actually improved during his last few years.

The article has received quite a bit of attention and both Yau and Andrew Gelman have commented on it in their blogs. There has also been feedback from Clemens's PR firm. Interesting reading!

[UPDATE] Justin Wolfers has provided a follow-up article on the Freakonomics blog with a "step-by-step" guide to his analysis. I don't know enough (yet!) about regressions and things like r-squared values to make comments on the analysis, but this seems like a great practical example for us to work through in Chapter 12.