4) One huge key to Rivers' renaissance. There wasn't a whole lot of publicity around Darren Sproles' departure from the Chargers three offseasons ago, but there was one awfully disappointed quarterback in San Diego. Philip Rivers lobbied the club to keep the diminutive gadget player back then, and after Sproles was poached by the Saints, it wasn't hard to find evidence on how it hurt the guy taking snaps. After three straight seasons with a plus-100 passer rating, Rivers' number dipped under 90 in 2011 for just the second time in his career as a starter -- and this happened again in 2012. So the Chargers signed a reasonably similar player this offseason, Danny Woodhead. And just like that ... Rivers is back. It's not the only reason for the rebound, of course, but it is an important one. Like Sproles, Woodhead gives Rivers a weapon underneath who can create and get first downs on his own, preventing Rivers from having to force throws downfield, something Mike McCoy looks to avoid. And also like Sproles, Woodhead is also a good pass blocker. That's a hard quality to find in those smaller types, and it gives Rivers a higher level of comfort against the blitz. A signing like Woodhead's will never grab headlines, but the effect it's had on Rivers is immense.