When Dak Prescott finished the 2016 preseason with a 137.8 passer rating, many observers talked about the "vanilla defenses" Prescott and the Cowboys faced.
"It’s only preseason," they said. "He won't look unstoppable against NFL defenses. He can't read NFL defenses yet."
But then he did.
That 'it's only preseason' argument is easily the most frequently used argument to discount preseason performances, be they good or bad. Dak Prescott is a case in point for how a good preseason performance can be argued away, and the QB apologists in Philly are a good example of how a bad preseason performance can also be argued away. Despite a 41.8 passer rating in the 2016 preseason, lots of people were getting ready to anoint Carson Wentz as the next big thing.
His QB rating came in at a pedestrian 41.8. But that figure doesn’t tell the whole story.
But it did.
Wentz would finish the 2016 regular season ranked as one of the worst QBs with a 79.6 passer rating, while Prescott finished the season as one of the best QBs with a 104.9 passer rating.
Granted, these are two cherry-picked examples where the 'it's only preseason' argument didn't really work; I'm sure there are a lot of cases showing the exact opposite.
But for backup QBs (both Prescott and Wentz were initially seen as backups for 2016) the preseason is often the only opportunity to publicly showcase their skills. Barring injury to the starter, the only action backup QBs are likely to see during the regular season is mop-up duty in blowout wins, and possibly in the last game of the season when playoff teams rest their starters. That's it. So preseason performance is important for these guys.
And a look back at the preseason performance of Cowboys QBs since 2012 is quite instructive in that regard.
The first thing that stands out when reviewing that performance is Tony Romo. Regardless of how healthy he was in the preseason, Romo always delivered strong performances:
|Tony Romo Preseason Perormance|
That's a strong and consistent passer performance over the last five years of his career - even if we face some sample size issues in 2015 and 2016.
So how do the legions of backup QBs the Cowboys have brought in over the years compare? Here's list of the other Cowboys QBs over the last six years, sorted by their preseason passer rating.
|QB Preseason Perormance, 2012-2017|
I've limited the list to QBs with at least 10 pass attempts. If I hadn't, Dak Prescott would lead the table with a perfect 158.3 preseason passer rating in 2017, but on just eight pass attempts.
Prescott's rookie season obviously stands out in this table with his 137.8 passer rating. And right behind Prescott, this year's rookie sensation Cooper Rush sits pretty with a 125.2 passer rating, which is miles ahead of any other recent Cowboys QB not named Tony Romo or Dak Prescott.
Does that mean Cooper Rush is a franchise-quality QB on par with Romo and Prescott? Probably not.
What is does mean is that Rush has performed much better than most other backup QBs the Cowboys have tried over the years. Sure, there are still two preseason games left, and his stats might not look quite as stellar if he throws a few interceptions.
But consider this: Rush could throw 26 consecutive incompletions over the next two games and would still have a better passer rating than Kellen Moore currently has.
Yesterday the Cowboys started giving Rush some 2nd-team reps in practice, and soon they'll have to take a decision on whether to keep Rush on the 53-man roster or release him and risk having him signed by another team. And that risk is very real.
The last time the Cowboys tried to sneak a QB with a similar preseason performance onto their practice squad didn't work out quite so well: Matt Moore finished the 2007 preseason with a 100.1 passer rating (21 of 29 pass attempts for 182 yards, one touchdown, no interceptions), and was picked up off waivers by the Carolina Panthers.
It's way to early to say how good a QB Cooper Rush could potentially be. But even if his ceiling is “just” that of a Matt Moore, that's still a lot better than anything the Cowboys have had at the backup spot for quite a while.
The Cowboys still have oodles of time to decide the semantics of whether they want to call Rush their QB2 or QB3, but they have just 11 days to decide whether to keep him on their 53-man roster. The one thing they won't be able to do is sneak him onto their practice squad. His preseason performance has turned too many heads around the league for that plan to have any chance of succeeding.