It's well-established that Tom Brady and Peyton Manning are the best two quarterbacks of their generation. And when it comes to how the future Hall of Famers stack up against each other, by most measures Brady wins out.

And now a new metric suggests that Brady is the best quarterback of this era, and perhaps any era.

With the Patriots' win over the Tampa Bay Buccaneers on Sunday, Brady notched his 139th win. That makes him the first quarterback in NFL history to have 100 more wins than losses:

Brady's regular-season winning percentage (.780) was already the highest among any quarterback ever. He is followed by Roger Staubach (.746), Joe Montana (.713) and Manning (.692).

Brady can attribute his superb winning percentage to a few factors: Longevity (he has started at least 14 games in all but one of the past 12 years) and an incredible run of success (the Patriots have won double-digit games ever year since 2003).

Manning has 157 wins and 70 losses, so to catch Brady he would have to rack up 13 more victories than defeats over the duration of his career. Not impossible by any means, but it would require the Broncos to maintain their high level of play this year and the next.

Other than Manning, no active quarterback is even close to Brady's mark. Here's a look at the top six:

1. Tom Brady, 139-39
2. Peyton Manning, 157-70
3. Ben Roethlisberger, 87-42
4. Philip Rivers, 71-44
5. Drew Brees, 102-70
6. Eli Manning, 78-60