Why backup quarterbacks don’t actually matter in the NFL

In between fits of unjustified worry over Dak Prescott’s shoulder and speculating how much the defense can improve under Dan Quinn, the Cowboys’ offseason has also featured some concern over the backup quarterback spot. It was apparently an issue for the coaches too, as Dallas worked out a few free agents and looked at some late-round options in the draft.

Well, they ultimately began training camp with a three-way battle between Garrett Gilbert, Cooper Rush, and Ben DiNucci. Rush was the only one to make the team’s initial 53-man roster, but then the Cowboys claimed Will Grier off waivers Tuesday. Which one is actually QB2 on game days remains to be seen, but the concerns over the backup spot don’t seem to have really been alleviated just yet.

But does it even matter?

There is a certain amount of weight placed on the position of backup quarterback that’s understandable at first blush. The quarterback is the most important player on the field at any given time, and despite how much the league tries to protect its quarterbacks they’re not impervious to injury, so it would stand to reason that having a good backup quarterback matters.

The reality is probably that backup quarterbacks don’t matter unless the team in question doesn’t have a great quarterback. Think about it: how often have teams with upper-echelon, elite quarterbacks actually succeeded when their star goes down? Dak Prescott is an obvious example, but beyond him? Matt Cassel played very well in 2008 when Tom Brady got hurt, but his body of work away from the Patriot Way suggests that had little to do with him. Case Keenum’s 2017 season was spectacular, derailed only by Nick Foles’ equally great 2017 season, but neither have done much of note before or since.

Furthermore, these are all exceptions to the rule. Some names you didn’t think of are Stephen McGee, Kellen Moore, Matt Cassel (but in Dallas), Sage Rosenfels, Austin Davis, Kellen Clemens, AJ Feeley, Dan Orlovsky, Seneca Wallace, Brian Hoyer, Ryan Mallett, or Curtis Painter. That’s three times as many examples just off the top of my head.

Then there’s the most recent example, which is the 2020 Dallas Cowboys. After signing Andy Dalton, the Cowboys had arguably the best backup quarterback in the NFL. Just for fun, I did the research on every NFL team’s backup quarterback last year. Only five backups had been in the NFL longer than Dalton, only two had more career starts to their name, and only one had a higher career QBR (after adjusting for the Chase Daniel’s and Taysom Hill’s, who had ridiculously high QBR thanks to a very low number of attempts). That one backup was Joe Flacco, so there’s a case to be made that Flacco, not Dalton, was the best backup last year.

Either way, the Cowboys had an incredibly good backup quarterback - 133 career starts, 70 career wins, and 52.4 career QBR is rare to find in a backup - and it ended up doing nothing for the team when Prescott went down. There was a brief stretch of games where Dalton got into a groove, the defense showed signs of life, and Dallas strung together a few wins. But those were wins against similarly bad teams. The fact that the Cowboys’ offensive efficiency didn’t change dramatically between Dalton, Gilbert, and DiNucci is telling. It’s not so much that Dalton was just bad - his body of work suggests a slightly-above-average player - but that the ceiling for backup quarterbacks is very, very low.

This makes sense, especially if a team has a great quarterback, as Dallas does. Obviously the offense will be tailored around said quarterback’s talents, which makes it very hard for anyone else to simply jump in and take over without at least an adjustment period.

If Prescott goes down for an extended period of time, it likely doesn’t matter who the backup is because the season will be lost. If Prescott has to miss a couple of weeks or so, then the desired backup quarterback is someone who has the ability to operate within the scheme without changing things too much and at least keep the team competitive.

Cooper Rush’s experience with both Dak Prescott and Kellen Moore make him a fit for that criteria, while Grier has some raw physical traits that could pair well with the concepts Moore likes to use. Both are the type of guys a team can make due with for a couple of games, but that’s about it.

Historically, it seems that’s really all anyone can reasonably expect from a backup quarterback anyway. Obsessing over finding the right backup quarterback is likely a pointless exercise. You can get an average, not-terrible performance for a couple of games from almost anyone. Anything more is just icing on the cake, but not something to reliably plan on having. Regardless of who the backup quarterback is - unless Andrew Luck is dying for a job - the Cowboys’ season rides on Dak Prescott.