I was reading John's post about who'll have the most impact on the upcoming year's outcome, and I kept reading that it was on Rivers shoulders to step his game up. Naturally, I started to wonder why he had such an outlier year last year.
This is my theory/opinion(should we believe he was not injured):
In my opinion, he was throwing so many INTs this year because of a lack of the effectiveness of underneath-safety valve type routes being run by our supposedly shifty/quick acceleration, slot Wes Welker type of receivers in Patrick Crayton, Bryan Walters, and Richard Goodman. Add that with the early injury woes of Antonio Gates, departure of Darren Sproles, and growing receiver pains of Ryan Mathews, and Rivers had to force the ball into tight windows against the perceived holes in the zone or man coverage.
From my recollection, Rivers effectiveness in previous years hinged on Darren Sproles/Antonio Gates being mismatched against slower linebackers in coverage: throwing the flat/wheel with LT/Sproles, throwing the pivot to Gates against linebackers, and dropping bombs on teams when their safeties cheated up to help the linebackers, leaving for 1-on-1 jump ball type scenarios. Obviously there's more to it, having neglected the whole of the running game, but having such good underneath players helped.
So what did Norv do this offseason? He brought in a bunch of proven, quick-twitch, true speed receivers in Robert Meachem, Eddie Royal, Roscoe Parrish, Michael Spurlock, and kept Richard Goodman. Gates appears healthier, and Ryan Mathews will hopefully keep improving in both the passing game and his running game now that he's actually had an offseason.
Obviously, this is just one idea I had regarding optimism for El Capitain's future and is entirely my opinion.