A Statistical Defense of Josh Rosen

Joe Nicholson-USA TODAY Sports

Over the last 20 years (1999-2018), there have been 57 quarterbacks taken in the first round of the NFL draft. Josh Rosen falls into this category, and his much maligned performance from last year warrants further review. This article will examine important statistics for first round rookie quarterbacks taken over the last two decades, and examine those statistics through the lens of team offensive success and the theoretical career progression those stats project.

First, a few important notes. Of the quarterbacks selected in the first round, only 23 out of 57 went on to make at least one Pro Bowl, which equates to roughly 40.4%. Less encouragingly, only 4 of those 57 went on to earn 1st team All-Pro honors, for a whopping 7%. What does this suggest? That over the last 20 years, drafting a quarterback in the first round is actually more likely than not to result in a non-Pro Bowl caliber "franchise" quarterback.

One note before diving into the meat of this article - my impetus for writing this piece was to offer a statistical defense of Rosen in light of all the chatter about Kyler Murray being the next QB of your Arizona Cardinals. While I see the merits, I want to again highlight that only 40% of recent 1st-round QB's go on to make a single Pro Bowl at any point in their careers. The book is still out on Rosen as a player, but let's say that Rosen is roughly half as good as a standard 1st rounder. He now only has a 20% chance to make a future Pro Bowl and only 3.5% chance to be a first team All-Pro. If you consider Murray 50% better than the average first-round prospect, that increases the likelihood that he is a Pro Bowler to 60%, and the likelihood that he's a 1st team All-Pro to around 10.5%. Now you are looking at a 40% chance that he never makes a Pro Bowl, and a 90% chance he's never a first team All-Pro. This is assuming that Murray is so much better a prospect that I'm giving him 3x the chance of outperforming Rosen! Is that risk worth dumping Rosen for underwhelming draft capital, additional dead cap, and the first overall pick - not even considering the opportunity cost of losing the chance to improve another deficiency elsewhere on the roster? You be the judge.

Officially hopping off my soap box, let's take a look at the stats. For this article, we will consider completion percentage, TD%, Int%, and a few team offensive stats to help position some of these issues. These QB numbers were chosen because they normalize performance across playing time. (Additional note: Dante Culpepper and Carson Palmer did not take any snaps as rookies. While they are part of the official count of 57 first round QB's, they were not included in the statistical calculations below.)

Completion Percentage

Josh Rosen completed 217 of 393 passes for a paltry 55.2% completion rate. This is, by all measures, fairly miserable. The average completion percentage across all passes thrown by 1st round rookie QB's in this study, however, is 57%. Had Rosen completed only 8 more passes across 2018 (less than 1 per start), he would have been above average in this measure. 27 quarterbacks register with a lower completion rate than Rosen over their rookie campaigns. Interestingly, Andrew Luck, Eli Manning, and Matthew Stafford are all players with reasonable sample sizes that completed a lower percentage of their passes.

Grade: Average (28th out of 55)

Touchdown Percentage

This measure considers the number of touchdowns against the number of passing attempts. Rosen threw for 11 TD's across his 393 attempts, which brings him in at 2.8%. The average was roughly 3.5%, which means Rosen would have needed to throw for three additional touchdowns to come in above average. Notable rookies that scored lower in this regard include Carson Wentz, Jared Goff, and Mitchell Trubisky.

Grade: Below average (37th out of 55)

Interception Percentage

Rosen's rough run continues as we consider his interception percentage. 14 of his 393 attempts were intercepted, good (or not so good) for a 3.6% rate. League average was roughly 3.3%, however, which means that had he thrown only 1 less interception for the year, he would have landed right in the middle. First rounders with a higher interception percentage include Sam Darnold, Ben Roethlisberger (who managed to win all 13 of his rookie starts), and Deshaun Watson.

Grade: Slightly below average (33rd out of 55)

Passing Yards

Rosen comes in above average here with his 2,278 yards for 2018. This stat, however, is largely influenced by the number of attempts the QB has - and so it unfairly skews the results toward those that received more playing time. Still, it's nice to see him on the right side of average for once.

Grade: Slightly above average (23rd out of 55)

The preceding stats paint the picture of a fairly underwhelming rookie. His overall grade across some of these raw statistics indicates a quarterback that performed slightly below average when compared with 20 years worth of 1st rounders. It is important to note, however, that the talent around a rookie makes a huge difference in their success. To help paint a better picture, I turn to some team numbers that attempt to present an overall offensive picture.

Plays From Scrimmage

This statistic was chosen as a makeshift measure for an offense's ability to stay on the field. Keep in mind that the numbers were across all 16 games in each instance, and these rookies may not have started in every game. Thus, we are looking at the team as a whole, including any games or snaps that did not include the rookie QB's.

The 2018 Arizona Cardinals had a meager 902 plays from scrimmage. We all know the team had trouble sustaining drives and keeping the offense on the field. For reference, the average number of plays from scrimmage across these 55 rookie campaigns was 1004. 1004! That means the Cardinals were 102 plays below average, which is roughly 1.5 games worth of offensive plays lost in comparison to the average offense inherited by a first-round QB.

Grade: Failing (53rd out of 55)

Yards per Game

This is the popular measure for offensive rankings, using the offensive yardage gained as a barometer for success. Unsurprisingly, Rosen's Cards were abysmal in this regard as well. The average offense gained 315 yards per game, while the Cardinals and McCoy/Leftwich's uninspired play calling averaged 241.6 yards. Yikes.

Grade: Failing (52nd out of 55)

Points per Game

Sure, yardage is nice. But you have to score points to win the game! Again, this is an attempt to paint a picture of team offensive success. The average first-round rookie QB led offense scored 19.9 points per game across these two decades, and the Cardinals managed... 14.1. Another ouch. (Side note - this does not account for any defensive points scored, so our offensive output was actually lower. The same could be said, however, for all other PPG rankings here.)

Grade: Failing (52nd out of 55)

Offensive ranking (YPG)

As discussed, yardage is not the only measure of an NFL offense. However, to further highlight the Cardinals' 2018 ineptitude, they finished dead last in the league at 32nd in overall offense. The 31st ranked offense, the Miami Dolphins, averaged 289.9 yards per game. You read that right - the second worst offense in the NFL last year managed to gain 48.3 more yards per game than us, which equates to 772.8 more yards across a 16 game schedule. The second worst offense in the NFL gained 773 more yards than the Cardinals last year!

So What?

There are a few interesting things to point out here. First, consider the fact that Rosen, while quarterbacking the worst offense in the NFL in 2018, managed to put up slightly below average passing numbers. Any fan of the Cards knows that we were routinely behind early in games, and made only half-hearted attempts to keep the running game going while we tried to come back time and time again. The porous offensive line, repugnant play calling, and change in offensive coordinators midway through the season put Rosen into a position that was destined for failure. Defenses could sit back and play passing lanes more aggressively, knowing they didn't have to fear the run as much while playing with a lead. Even with all of these obstacles, Rosen managed to land near the middle of the pack in most of the playing-time adjusted statistics.

Secondly, I want to discuss sacks. Here are the sack totals for each of the 2018 rookies:

Rosen - 45

Darnold - 30

Allen - 28

Mayfield - 25

Jackson - 23

While none of these QB's were full year starters, Rosen managed to get sacked 45 times in 2018. Darnold comes in second at 30. To put this in perspective, Mayfield, Darnold, and Rosen each started 13 games in 2018. Rosen was sacked 15 more times across those games, meaning he was sacked at least 1 more time in every game he started than rookies with similar snap counts. Rosen was sacked on roughly 5% of all offensive plays that the Cardinals ran in 2018. Keep in mind, this number actually increases when you consider that Rosen was on the bench for about 1/4 of these plays across the year (as it would for the others). For reference, here is the same stat for the other 2018 rookies:

Darnold - 3.1%

Allen - 2.8%

Mayfield - 2.4%

Jackson - 2%

This is an imperfect statistic, but paints a picture of a pocket-passing quarterback that was under constant duress. While more mobile players like Mayfield and Allen could potentially use this to their advantage, Rosen is not the type to look to consistently escape the pocket. Rosen took his hits like a champ, and showed a lot of mental fortitude in an abysmal 2018 season.


While Rosen's 2018 season was not great, there are mitigating factors to consider. His completion percentage, TD%, and INT% were all below average relative to other first round rookies, but he was tasked with leading one of the worst offenses any NFL team has trotted out over the last 20 years. Between a change in offensive coordinators, being thrust into early action behind a highly underwhelming veteran bridge QB, and running for his life behind an offensive line that kept exactly zero of its' projected starters healthy for the year, it's hard to see how any rookie QB would perform well. Still, a below average start to Rosen's career can be nothing but expected given the atrocious offense he was "gifted."

There is a statistical argument to be made that Josh Rosen actually performed better than would be expected given the abysmal offense he played in, especially as a rookie. It is also important to consider that a poor rookie campaign is not a guarantee of future failure, nor is it a guarantee of future stardom. While Rosen's future is still largely unknown, giving up on him at this point is not borne out by his statistical performance relative to other first-round QB's and the offenses they led.

<em>This is a FanPost and does not necessarily reflect the views of Revenge of the Birds' (ROTB) editors. It does reflect the views of this particular fan though, which is as important as the views of ROTB's editors.</em>