On Thursday, Dan Mullen spoke about quarterback accuracy during his Thursday press conference. Some readers took that as an opportunity to point out to me that we disagree on this topic.
@WillMilesSEC mullen doesnt agree with your accuracy stats on qbs😂 https://t.co/hVuEr0fYK7
— 🐊JOSH🐊 (@joshgatorgann) April 4, 2019
— Unique Produktionz (@Unique863) April 5, 2019
First off, it’s okay to disagree. I’m not always going to be right. And while he’s forgotten more about football than I’ll probably ever know, Mullen isn’t always going to be right either.
But I don’t really think we disagree here.
Mullen’s point during the press conference was that improvement in accuracy can’t just be measured with completion percentage. Instead, he focuses on ball placement on each throw and how to improve that.
I agree with that assessment, but maybe not for the same exact reasons.
Is completion percentage an important statistic?
I don’t think there’s much debate here.
Completion percentage is a really important indicator of QB success. We can see this clearly if we plot completion percentage versus QB rating from 2005-2018 for QBs with more than 14 attempts per game.
Completion percentage versus QB rating of QBs from 2005-2018. (Will Miles/Read and Reaction)
There’s a pretty clear correlation between the two statistics. Better QB play does track with completion percentage.
Indeed, if we look at the 252 QBs who had QB ratings higher than 150 – which represents very good, but not elite, QB play – only 5 of those QBs (2.0%) had completion percentages below 59.2. Only 12 had completion percentages below 60.
The two red data points are for Feleipe Franks in 2017 (triangle) and 2018 (square). What this indicates is that Franks’ completion percentage in 2017 was completely in-line with his QB rating while he outperformed his completion percentage in 2018. There are QBs who have had lower completion percentages and better QB ratings, but not very many.
The importance of completion percentage also is observed for winners of the Heisman Trophy. Nine of the last ten winners have had a completion percentage above 66.1.
The one player who did not is Lamar Jackson in 2016, when he completed 56.2 percent of his passes. Of course, Jackson also ran for 1571 yards on 260 carries, which is a better season running the ball than Ciatrick Fason had for Florida in 2004 (222 carries, 1267 yards).
The average completion percentage for those past ten Heisman Trophy winners is 67.3 percent. It seems like that indicates that it’s a pretty good stat to keep track of.
Accuracy vs. Decision-Making
Completion percentage is a measure of how often a QB completes a pass, which must mean that it measures accuracy, right?
Well, it depends on how we define accuracy.
If we define accuracy as the ability to give the receiver the ability to run after the catch, completion percentage doesn’t really measure that.
An example of this is shown on this play, where Franks double-clutches and then delivers the ball behind Kadarius Toney. Had the ball hit Toney in stride, this is an easy first down but still is likely only advanced another 3-4 yards down the field. That’s a significant thing as far as the game is concerned, but is not reflected in completion percentage.
Another example is shown here. Franks correctly diagnoses the play and finds a wide open C’yontai Lewis streaking down the sidelines. The ball is thrown on a rope and just slightly too far and Lewis makes a fantastic diving catch. This is a huge play, but had the ball been thrown just slightly better, Lewis might have had an opportunity to cut back inside and score.
In both of these cases, we’re defining accuracy as the QB putting the ball exactly where he wants it so that his receiver is put in an advantageous position. Both of these balls were completed, but they could have been completed in a more accurate fashion.
So that’s one definition of accuracy. But what if we define accuracy as the ability to make completions easy – where ball placement isn’t absolutely critical – instead of having the fit the ball in perfectly.
Well, I do believe that this is highly correlated to completion percentage. And it has a lot more to do with decision-making and reading a defense than it does the ability to throw the ball to an exact spot on a frozen rope.
An example of what I’m talking about can be seen in the above play. Franks is in trouble, throws the ball off-balance, and throws a little bit of a duck. But Josh Hammond is so wide open that even though the ball hangs, it is still a big completion.
Now, had Franks hit Hammond in stride, this may have been a touchdown. But because he was throwing to the correct receiver who would be open against this coverage, he had a much larger margin for error. It’s an interception if it’s not thrown to the correct receiver instead of a completion.
This play is just before the diving catch by Lewis. It’s second-and-6, so there is value to gaining just a few yards. Franks is able to avoid a sack by chucking the ball into the sidelines. But he misses a completely wide-open Lamical Perine as a safety valve. It’s an easy throw, and likely an easy first down.
We can see the same thing against Florida State. On this play, Franks fakes the QB run (which had been effective just the play before) to move the coverage to the left. He then comes back to the right against the zone and hits a wide open Trevon Grimes. Again, there was a large margin for error on this throw.
It is absolutely true that a QB is going to have to hit difficult throws that he must fit into tight spaces and place perfectly. But it is also true that there will be plenty of opportunities where the QB can defeat the defense with his mind – by diagnosing the correct place to go with the ball – instead of with his arm.
Completion percentage has a difficult time measuring the first. I think it does an excellent job of measuring the latter.
Can accuracy and decision-making improve?
I have no doubt that Mullen’s assertion that the way to improve accuracy is to improve ball placement is true. I also suspect that it’s improving a player at the margins because the decision-making aspect of accuracy is an inherent trait rather than a taught one.
Percentage of QB’s with a certain change in completion percentage from high school to college. (Will Miles/Read and Reaction)
The above chart is an analysis of 50 QBs whose high school stats I’ve been able to find. It compares their completion percentage in their senior year of high school versus their college completion percentage. The average high school completion percentage of those 50 QBs was 62.0. The average in college? 62.1.
We do have to recognize that there are outliers. But only 10 percent of those QBs have seen an increase by more than six percent. Based on this sample – admittedly limited – over 60 percent of QBs will end up between 3 points less and 6 points more than their high school completion percentage.
This has been true for Feleipe Franks in his first two seasons. Franks had a high school completion percentage as a senior of 58.9 percent. He has completed 56.8 percent of his passes at Florida, and completed 58.4 percent under Dan Mullen last season, exactly where you would expect him to be.
The argument that he will show improvement in this area like Drew Lock or Matthew Stafford is convincing on its face. Lock’s completion percentage in college improved from 49.0 to 54.6 to 57.8 to 62.9. Stafford’s improved from 52.7 to 55.7 to 61.4. However, Lock had a completion percentage his senior year of high school of 66.0 with Stafford at 64.9.
Basically, those players were finally able to reach their potential while it appears Franks may have already reached his. Of course, many people also point to the dearth of coaching that he received in high school and then until Mullen came into the fold at Florida. Perhaps that means he’ll be an outlier.
After all, one of those outliers was Nick Fitzgerald, who saw an increase in completion percentage of over 10 points.
Takeaway
This may seem like a bunch of semantics, but it’s actually pretty important. That’s especially true when you are trying to identify whether a high school QB that your team is recruiting is going to be a game changer for your program.
I was able to find high school completion percentages for eight of the past ten QBs to win the Heisman Trophy (couldn’t find for Robert Griffin III or Sam Bradford). The relationship between college and high school completion percentages is striking.
Accuracy of eight of the last ten Heisman Trophy winners in high school and college. (Will Miles/Read and Reaction)
I can understand why you maybe didn’t see Baker Mayfield being as good as he turned out to be at Oklahoma. But we should have known that he would be at least a good QB with the ability to put up a QB rating of over 150.
In fact, I got this wrong last year thinking that Oklahoma would take a step back under Kyler Murray. My rationale was that Baker Mayfield was so good that even if Murray was great, he couldn’t be that good. It turns out he was, especially when you factor in his running ability. Had I looked at his high school stats, that would have told me something different.
None of this means that you can’t have a very good QB who doesn’t have an elite completion percentage. But it sure makes things a lot harder.
Mullen is going to make Franks better by working on ball placement and timing. He’s going to make the offense better by using the threat of a running QB to open up other aspects of the offense and make reads easier. All of those will help Florida move the ball and helped the Gators move the ball in 2018.
But regardless of how you want to define accuracy, there’s no doubt that completion percentage as a statistic is clearly related to QB effectiveness.