Forgive the Colbert reference for the moment, and forget that he just put up one of his iffiest performances of the season. Now let's ask the question: When Peyton Manning retires one day, will he go down as the greatest quarterback in NFL history?
It's a nearly impossible question to answer, for many reasons.
First, obviously Manning has a long way to go until retirement. His main lieutenant for a decade, Marvin Harrison, is out of the league, but Manning's still going strong, and may well be peaking right now - not an uncommon occurrence at a position where experience and smarts can matter as much as raw athleticism.
Second, what's the best way to gauge quarterbacks' performance against each other? This isn't baseball, where a home run is a home run, no matter the era. Football is a far more dynamic sport, having experienced huge changes over the past generation. QBs are far more accurate today than they've ever been (well except for you know who), QB ratings are much higher than they've ever been, and teams pass more than they ever have, with short passes even favored over run plays in many short-yardage situations. Newly-preferred stats such as Yards Per Attempt give us a better idea of quarterback performance across eras, though even then, how do you compare, say, a great system passer in a West Coast offense with some of the gunslingers of NFL days gone by?
Here's what we do know: Manning already ranks 5th all-time in passing yards and 3rd in passing touchdowns. On the flip side, he's just 13th all-time in YPA, behind such present-day luminaries as Matt Schaub. He also trails many of the most prolific winners of all-time, well behind legends like Terry Bradshaw and even current rival Tom Brady for Super Bowl rings. Of course, Manning has plenty of time to add some titles to his ledger, with the Colts either the favorites or co-favorites this season, depending on who you ask.
Other questions crop up:
If Manning isn't a candidate for greatest of all-time, what about simply most valuable? Where would the Colts be without him, given they usually lacked the Lawrence Taylor-like defensive superstars that other Super Bowl teams possessed?
Did Manning make Harrison and Reggie Wayne into the all-world receivers they became, or would they have been stars playing with Billy Volek too?
Or is there just too much noise to make a clear determination, in contrast to baseball, where Walter Johnson...uhhh, Cy Young...uhhh, Roger Clemens...or Greg Maddux...is the greatest pitcher of all-time?
Maybe these questions can't be definitively answered at all. What do you think?