Is Sam Bradford really an upgrade over Shaun Hill?

playAdam Schefter breaks down how the Vikings were able to acquire Sam Bradford from the Eagles. (1:39)Our story does not begin with the trade this past weekend that sent Sam Bradford from the Philadelphia Eagles to the Minnesota Vikings. Nor does it begin last Tuesday, when Teddy Bridgewater tore up his knee in practice and broke the hearts of a fan base anticipating its first playoff victory since Brett Favre was in town. Our story actually begins in mid-July, when the Football Outsiders staff was hard at work cranking out our annual almanac.

As I was writing the Vikings' chapter, I was struck by Shaun Hill's career passing numbers, which were surprisingly good for a guy who has never…