Three years ago, when Brett Favre first retired from the NFL, he held the league's all-time records for completions, passing yards and touchdowns -- but it sure didn't seem like he would hold those records for long. Peyton Manning's phenomenal numbers had him on pace to pass all of Favre's records except for the one Favre doesn't really want, the one for career interceptions.
Manning keeps plugging along with superb seasons, but Favre's continual un-retirements have been moving the goalposts farther and farther back. How good are Manning's chances to eventually set NFL records after Favre adds three more years of stats on to the totals from his career with the Green Bay Packers?
To figure out the chances of Manning -- and other quarterbacks, such as Aaron Rodgers, as framed in this debate -- eventually passing Favre's records, I adapted an old Bill James baseball tool called the Favorite Toy. The basic idea is to project how many seasons a player has left and compare that to his "established performance level" in order to find his odds of reaching a certain milestone.
The number of seasons a player has left is determined by a fairly simple equation: Start with the number 24, then subtract 60 percent of the player's age last season. Tom Brady, for example, is 33 years old; when you do the equation, he has about five years left in the NFL. Rodgers has about 8.4 seasons left.
The established performance level is calculated this way:
[(3*Total Last Year) + (2*Total Two Years Ago) + (1*Total Three Years Ago)] / 6
For Brady and Carson Palmer, because they were significantly injured two years ago, I used 2007 and 2006 instead of 2008 and 2007. Then, because Favre will play one more season, I added Favre's current "established performance level" to his career totals in order to get the "projected milestones" that the other quarterbacks will be attempting to match a few years from now.
What are the results?