Who is most likely to break Peyton Manning's touchdown record?


Who is most likely to break Peyton Manning's touchdown record? originally appeared on Quora: The best answer to any question. Ask a question, get a great answer. Learn from experts and access insider knowledge. You can follow Quora on TwitterFacebook, and Google+.

Answer by William Petroff

Most likely, the person who will break Peyton's career passing-touchdown record isn't in the NFL yet.

This ends up being a slightly complicated question, largely because we have no idea what Peyton Manning's record will be. He's on pace for about 45-46 touchdowns this season and we don't really know how long he's going to keep on playing. [1] Let's say, for the sake of the argument, that Manning ends up playing two more years to get him to the nice, round age of 40. That means we have to project what we might expect Manning to do in those two years, and the most basic way to project stat totals is to use a weighted average of previous seasons in a manner like:

where "i" equals the  previous season. Using somewhat standard methods, we might assume that he ends up 600-610 career touchdowns.[2] 

To put a more exact number on it, I'm looking at about 606 touchdowns, so getting around that 600-mark is good enough. That's a pretty large number of touchdowns. Of the current crop of quarterbacks, Andrew Luck has an outside chance, but he'd have to play virtually every game till he was 41-42 to really get it done [3]:

Breaking this record is going to take a pretty monumental task, requiring some combination of Favre's fortunate luck with health and Manning's big-time seasons. It's one of those things that you really can't give good odds on, even for the people who are projected to get to that 600-touchdown mark in a reasonable time-frame.

[1] At the beginning of the year, Manning seemed to embrace Brady's mantra of "playing until you suck," and he doesn't seem all that close to that level yet (though, "suck" will probably end up being relative in this case). And a not unreasonable attempt at projecting out a few years would suggest that "sucking" in an absolute sense could be a little bit longer than most might think. Peyton echoes Brady: Play "until you suck."

[2] Now, I said that I was using "somewhat standard methods" because I've modified this approach somewhat. Instead of using an individual's statistics, I've taken all quarterback seasons off quarterbacks who have played post-2000 in which a the quarterback started at least six games to create an average model to apply the weighted average too and then multiply that result by the ratio of a given quarterback's career touchdowns compared to what an average quarterback would produce over the same length of time. This ends up more realistically accounting for the aging process and the general skill curve:

[3] Two things: First, to state the obvious, the system that I'm using kind of craps out after age 47. Of course, in the system's defense, I'd think that most quarterbacks would crap out well before then.

Second, it's really hard to project anyone passing Manning in any realistic fashion because Manning has a built in advantage; he's had two 40+ touchdown seasons and is currently working on his third. Drew Brees is the only other quarterback to have more than one (both Brady and Rogers have come very, very close). Effectively, this means that Manning has thrown six seasons-worth of touchdowns in three seasons. Seasons like this are also pretty impossible to project; Luck tops out with touchdown totals in the high 30s over the course of the projection — this is, perhaps, the biggest drawback of using the "average quarterback" model — and, obviously, if he ever has a 50ish touchdown season, that will shave a year off his quest.