Every Thursday, Football Outsiders president Aaron Schatz contributes the Numbers Crunching piece to ESPN Insider; it previews every matchup in the NFL that weekend using FBO's unique metrics, which are best detailed here. Below is the Week 15 edition for 2009.
Some of the statistics in this article come from the Football Outsiders game-charting project, in which a group of volunteers watches every NFL game to track stats like play-action, blitzes, formations, and defensive coverage. Please note these numbers are incomplete; right now, we've charted roughly 70 percent of all downs this season.
Thursday Night Football
The Colts are the second-best offense in the league on third downs -- and the Jaguars are the third-worst third-down defense in the league.
Indianapolis and Jacksonville are the two least-penalized teams in the league; they're each penalized fewer than six times per game.