I had a post on this from another forum, I'll just c/p:
Tom Brady's pocket presence -- this entire season -- has been completely and utterly awful (edit: well, by *his* standards). It's so out-of-character too....
He used to be so calm and sure-footed in the pocket, too. Ron Jaworski used to call him the most "mobile" QB in the league -- not for scrambling (for sure) -- but for his ability to slide around in the pocket, unfettered, and make a solid throw with his feet still under him. He was great at it. Even after the ACL-tear, he wasn't bad at it. His pocket presence got worse, sure (mentally). But it wasn't awful. This year? It's awful. It's all mental too.
I think it's because he doesn't trust his offensive line. They aren't bad either. But Matt Light retried. Same for Brian Waters. Dan Koppen went to Denver. Logan Mankins tore his ACL (he actually left the game today, too). Vollmer is constantly injured (he left today's game, as well) So, a lot of new guys out there. That pretty much leaves Nate Solder -- who's in his 2nd year -- as his longest tenured, and healthy, starter. Solder is new to the LT position. So, now you got guys like McDonald, Wendell, Cannon, and Thomas; who have little experience, who are all in there at once.
I remember when people used to rag on Brady for getting too much time in the pocket. Now? When he does get too much time; it's almost, counter-intuitive, to his detriment. He gets visibly happy-footed, and doesn't set his feet when (or if) he throws.