Since they were nice enough to link over here, I thought I'd make it easy to find what they're referencing:
Beyond the Box Score: A National Look
BTBS Glossary
SMQ's Wonk Watch: Passing Downs vs Non-Passing Downs
TDs: The Runs Batted In of College Football Statistics (Part One)
TDs: The Runs Batted In of College Football Statistics (Part Two)
TDs: The Runs Batted In of College Football Statistics (Part Three)