Should Tony Romo or Dak Prescott Start for the Dallas Cowboys? 

It’s an old football truism that if you have two starting quarterbacks, you don’t have any. Right now, the Dallas Cowboys (5-1, #1 in the NFC East) are on their bye week. Tony Romo is due to return from a back injury he suffered on his second play of the preseason…and Dallas now has two starting quarterbacks.

Dak Prescott and Ezekiel Elliott have been certified rookie sensations, and Dallas’s league-best offensive line has been a major part of both player’s success so far. Since Week 1, the line out of the Dallas front office has been “We’ll start Romo when he’s back and fully healthy.” That position has been modified a bit, with current statements from Jerry Jones of “What we won’t know is what is the very best time, relative to his injury, his conditioning, what is the very best time for him to be on the field?”

Which, given Romo’s injury history, sounds like Jones is taking ‘fully healthy’ with a grain of salt, if not a small hot tub full of Ben Gay. Prescott is winning games, and there’s a deep conservatism in NFL coaching about “don’t break what’s actually working.”

The question becomes “What’s actually working?”

Prescott is currently completing 68% of his passes, and is maintaining a respectable 8.17 yards per attempt. His quarterback rating is 103.9, and is elevated by his 7 TDs to 1 INT ratio. If he can maintain that quarterback rating through the entire season, he’ll eclipse Robert Griffin III’s rookie record for quarterback rating. More impressively, he’s also done this without the benefit of having Dez Bryant on the field.

Prescott is a good intermediate range passer, and the running offense (and offensive line) are good enough that he doesn’t have to make expert reads on defenses. Anyone facing Dallas knows they’re going to see a steady diet of Ezekiel Elliott ramming the ball up the middle. He gets a lot of mileage out of play action passes off the running game, but it’s unknown whether he can truly beat a team with his arm.

To get a comparable snapshot of Romo, we have to go back to his 2014 campaign. During that year, Romo completed 69% of his passes, compiled a quarterback rating of 113.2, and dished out 34 TDs and 9 INTs. It was the best season of his career, and depending on if he ever starts again, it may be the definitive season of his career. Romo has now had three injury shortened seasons (2010, 2015, and this year), and hasn’t played a full 16 games since 2012.

Romo’s lifetime completion percentage is a touch lower, but his average yards per attempt is higher. Unlike Prescott, who has rapidly declining accuracy on the deep ball (and an offense that conceals this weakness by not asking him to make those throws), Romo keeps the deep ball play as a valid threat when he’s taking snaps under center. Prescott doesn’t.

Prescott is clearly the future in Dallas; he makes good decisions, and he works within his limitations on arm strength and accuracy. Good decision making is the gold standard of good quarterbacking at the NFL level, and Prescott is on a four-year rookie contract that’s chicken feed compared to Romo’s salary.

However, the future isn’t now. Defensive coordinators are going to get a library of tape on his game, and pick it apart. He isn’t using the full route tree in Dallas and he’s not using the entire playbook; those will come with more reps and more off-season work.

When it’s clear that defensive coordinators have caught up with Prescott’s development, probably later in the season, Romo makes an excellent “change up.” When Romo’s healthy, he’s a top-5 QB in the NFL; starting Dak Prescott now preserves Romo’s health for later-season starts, and for the playoffs.