I honestly don’t know how I didn’t see this article earlier. The gist:
No QB has performed so far below the league average for so long as Joey Harrington. To be clear, Joey Harrington probably isn’t the worst quarterback of all time in an absolute sense. But in terms of being so far below average, but far enough above miserable to earn more playing time, Joey Harrington hurt his team more than any other QB in NFL history. If Harrington had been worse, he would have played less, and he wouldn’t have set back the teams he played on. To put it another way, if you had the choice of getting Joey Harrington for 2,538 attempts, or Roger Goodell for 9 attempts you would certainly choose Goodell. At least after he’s gone, your team has a chance.
