Tom Brady contract analysis

With the Patriots and quarterback Tom Brady set to turn in the paperwork Friday on a four-year contract extension through 2014 -- news first reported by Sports Illustrated's Peter King -- it strengthens the likelihood that Brady will finish his career in New England.

Brady has said that he wants to play until he's 40. This deal takes him until he's 37.

One key detail is that the four-year extension will be tacked on to Brady's existing contract, which has one year remaining. So this ensures that Brady will be under contract for the next five years.