Love him, hate him, but never doubt him. That may stick in the throat of many Patriots haters, but with the gaudy statistics and five Super Bowl victories to prove it, Tom Brady seems to achieve whatever he wills. And what he wants, according to team owner Robert Kraft, is to play another seven years.

What makes Brady different, though, isn't a will to continue playing – we've seen the competitive fire of other great quarterbacks quenched by injury and age. Rather, it's that Brady seems to have a legitimate chance to play as long as he wishes.

It's an option not available to every player. Skill and economics factor heavily into how long a player lasts in the NFL, but the decision to retire is often made by MRIs and MDs. Tendons tear, cartilage shreds, the feet slow – and teams realize that the third-round pick can put up the same numbers at a lower cost.