If you enjoy great analysis on interesting football trends, I recommend visiting Chris Brown's smartfootball.com. He tends to focus more on the college game because there's more diversity of style and often more innovation on Saturdays, but I like his NFL stuff, as well. Anyway, here's a piece he wrote for Grantland breaking down Darrren Sproles and how the Saints really have their finger on the pulse about how to best utilize players like him. "Space" players. It's a great read. But if you read it and wonder if Percy Harvin could have even more potential, or frustrated that the Vikings seem lagging behind the curve on a number of fronts, you're not alone.