I took a look at some of Brady's stats from 2010 to 2016 (e.g., DVOA, completion and INT %ages), and put them on a graph. They're normalized relative to 2010, and the vertical line represents the 2014 preseason where they drafted Garoppolo.
The key here is that there was a clear downward trend from 2010 to 2013, and then a clear rebound since then.
View attachment 16804
So, is Brady's performance the last three years the result of him "finding the fountain of youth" (i.e., something that will last for years) or a sort of "Indian summer" that will end soon?
What BB thinks is the answer to that question will go a long way in determining what the Pats do with Garoppolo.