For every comeback win there is a corresponding comeback loss, and one cannot be considered without the other. A comeback win occurs when the winning team overcomes a deficit at the start of the fourth quarter, at sometime during the fourth quarter or, if necessary, in overtime. Comeback wins have little to do with “comeback opportunities,” as the latter deal specifically with a point spread of eight or fewer points and include games that are tied in the fourth quarter. A comeback win can occur from any deficit and doesn’t deal with ties.
For the purposes of this study, I have made no attempt to credit a QB’s total of comeback wins/losses based upon whether or not he deserves them, as luck always plays a role. My totals are entirely based upon one criteria---who was the QB of record when the comeback win or loss was attained, regardless of how it was attained. As an example, I didn't credit Dan Marino, John Elway, Kerry Collins, and Warren Moon with comeback wins when they were injured during a game-winning drive and replaced by another QB. To do so would ignore the element of luck. Also, my calculations are based upon “QB starts” rather than “games played”, as it would be extremely unfair to use the latter stat for many of the QBs. “QB starts” isn’t perfect either, as several of the QBs mentioned here scored comeback wins or losses in relief.