One of the more fun thing to do with statistics is a deep dive where you get to test conventional wisdom. Conventional wisdom is often trusted without really diving deep and testing it out. It is just generally accepted and people move on. In this case, the conventional wisdom says you have to give a quarterback three to five seasons to develop until you figure out whether they can be a solid to good starter in the NFL.
It makes sense. People even point to examples to prove it. Josh Allen was no great shakes in his rookie season. Patrick Mahomes and Aaron Rodgers didn’t even play in their rookie seasons. Obviously, it took a little while for Tom Brady to become Tom Brady. Peyton Manning led the world in interceptions as a rookie. These handful of examples would seem to prove the point. Except, maybe they don’t. Maybe they are exceptions that people remember.
Naturally, we bring this up because we have a young quarterback in the building. He had some good moments and some really bad moments. The aggregate would say he was solid, but not spectacular. Is there hope that he could develop into a top 15 starter in the league or is he destined to be a second tier starter or good backup? Obviously, no one knows for certain what the answer is, but we can look to the recent past to see what the likely answer will be.
The first thing we did is break the NFL into two groups of quarterbacks. There are consensus top 15 guys and then there is everyone else. Granted, some quarterbacks in the second group might actually belong in the first group. We will address those situations individually. That means by strict definition that some top tier guys really aren’t top tier guys. What we did is simply look at what each player did the first time they became a starter or had significant snap counts. The general implication is whether they started off with a bang or if they grew into their greatness as conventional wisdom says.
We did the same thing with the second group of guys. Maybe some of them showed out and then regressed. We can certainly highlight individual cases, but the idea is to get an aggregate or baseline expectation. Essentially, how likely are our first impressions to be on the money?
In this case, we took three different statistics from three different sources. I am looking at PFF grades as I have done before, but I’m not relying on that alone. I’m also including the old-fashioned quarterback rating, and ESPN’s QBR for good measure. I will report the general data first with the highs for each, lows for each, and the average for each. We will then take a look at Mills and the other rookie quarterbacks and compare them with some specific players.
It should be noted that the top 15 guys aren’t necessarily exact because we are talking about a consensus and not necessarily the top 15 guys from last season. Conventional wisdom is sometimes wrong and sometimes guys are labeled as one thing when they are really another. We can break down those guys individually in some detail.
Average PFF: 70.8
Average Rating: 90.4
Average QBR: 62.4
Often times it makes more sense to talk in generalities because high and low numbers can skew the results. Four of the 15 quarterbacks produced rookie PFF scores below 60. Three of 15 produced quarterback ratings below 80. Only one quarterback produced a QBR under 40 in his rookie season (or the first season where he had significant playing time).
Conversely, we see slightly different numbers with the bottom 15 quarterbacks. Again, if we take a few out and add them to the top half of the list we see the numbers change radically. We will discuss those cases in a minute. For now, we will stick with the overall data to see if we find any trends.
Average PFF: 66.5
Average Rating: 82.5
Average QBR: 47.6
If we do the same thing we did with the top half we find some key differences. Only two of the 15 quarterbacks scored above a 70 in PFF in their first season (eight did that in the upper half). Only two scored above 90 in quarterback rating (seven did that in the upper half). One quarterback scored higher than 60 in QBR in the lower half as compared to nine in the upper half.
We discuss outliers for two reasons. First, it is the intellectually honest thing to do. Secondly, it can help explain the overall results. Three quarterbacks on the lower half of the ledger are arguably top tier quarterbacks. Debating quarterback tiers is a blast, but for simplicity sake we will just say that Jimmy Garrapolo, Baker Mayfield, and Ryan Tannehill are difficult to peg one way or the other.
Ironically, two of those quarterbacks are available on the trade market. If we were to add those guys to the upper half and call it the top 20 then the PFF grade would go up, the quarterback rating would remain at about where it is, and QBR would go down slightly. If we elevated them and demoted Derek Carr and Lamar Jackson then the scores would be even better.
It’s what happens to the lower scores when we remove those three that is the most stark. The PFF grade drops to 63.3. The quarterback rating would drop to 81.0. The average QBR would drop to 44.3. Again, we are not litigating the placement of those five particular quarterbacks here, but if you would like to hash it out in the comments then have at it.
Where is Davis Mills?
Mills came in with a PFF score of 58.5, a quarterback rating of 88.8, and a QBR of 35.5. So, he falls well into the second group in two out of the three categories. Bill James (a famous baseball statistician) developed something called “similarity scores”. The whole idea is to compare players with similar players throughout history. If we do the same based on the numbers from these quarterbacks we find that he is most similar to Jalen Hurts and Drew Lock. If we are being ambitious we could compare him with Andy Dalton.
Davis Mills: 58.5 PFF, 88.8 rating, 35.5 QBR
Jalen Hurts: 58.2 PFF, 77.6 rating, 33.8 QBR
Drew Lock: 58.1 PFF, 89.7 rating, 50.2 QBR
Andy Dalton: 62.2 PFF, 80.4 rating, 49.5 QBR
You’ll notice that all four quarterbacks were decidedly below average in most of the categories in their first year with significant playing time. As a Horned Frog alum, I love Andy Dalton. He quarterbacked our team to a Rose Bowl victory (and undefeated season) over J.J. Watt and the University of Wisconsin. He has had a solid career since then. No one is calling him an upper echelon quarterback.
Jalen Hurts and Drew Lock are still relatively young, but the Seahawks are likely scouring the market for an upgrade over Lock. The Eagles seem content with Hurts for now, but most observers don’t think he’s breaking into that top group. The debate over Mayfield and Garappolo will be fierce, but Mills isn’t likely part of that debate. He is either a fringe starter or a really good backup. That’s good for a third rounder, but it’s not something you build your franchise around.