Links with Data: Stop Worrying and Love the Bomb

| March 7th, 2019

By Andrew Link

In part 2 of this crossover series (that nobody asked for), Johnathan Wood and I will take you on a journey of expectations for the third-year Bears quarterback. As discussed in part 1, Mitch Trubisky has struggled with the deep ball. There were a myriad of reasons why but the gist of it is this: Trubisky was below league average, threw almost as many deep passes as anyone in the NFL, and for this offense to take a leap in 2019, that particular portion of the game needs to improve.

Esteemed data man Johnathan Wood has come up with some theories of his own and you can read about those here. And I urge everyone to go and read the full article at Da Bears Blog. But for the sake of simplicity, I will take a few excerpts from said article and share those with you all.

To approach this from a statistics perspective, I used the Pro Football Reference Game Play Finder to break up raw passing statistics into deep (15+ yards down the field) and short (<15 yards past the line of scrimmage). I looked at 19 quarterbacks who were starters in 2018 and had been playing consistently for at least 4 years (full data here). I’ll note that data for deep passes only goes back through 2008, so that’s as far back as I was able to go for QBs who have played longer than that.

Here’s what I found: while some quarterbacks are certainly better deep passers than others, the amount of year-to-year variability for each quarterback is greater for deep passes than short passes. That can be measured through the standard deviation for each quarterback, which expresses how much they vary from year to year in a given statistic (bigger number = more fluctuation). I found this for each quarterback for the main passing statistics, both short and deep, and then averaged them together for all 19 quarterbacks in each category. The results can be seen in the table below.

Pay particular attention to the ratio. That’s a rough measure of how much more variable deep passing statistics are to short ones for a given quarterback from year to year. Yards per attempt and interception percentage are both more than 4 times as variable for deep passes as short ones. That is excellent news for Bears fans, given Mitchell Trubisky’s high interception rate on deep passes in 2018.

I found this to be interesting. This makes sense to a point. Surely throwing the ball deep is going to have some level of pure luck, and as you will see in the videos, there is certainly an element of luck to it. It also makes sense that the deeper the throw, the farther off-target misthrown balls will be. Imagine being able to hit your driver 320 yards and being off by a few degrees. A much larger margin of error than say, someone who hits their 3 wood 230 yards.

Worthy Adversaries

But luck can’t be everything, can it? There has to be more to it than that. I decided to look at some of the other quarterbacks in the league to see what I can key on as areas of improvement for Trubisky as he heads into his 2nd year under head coach and playcaller Matt Nagy. I scoured the tape of some of the best deep ball artists in the NFL: Aaron Rodgers, Drew Brees, Tom Brady, Ben Roethlisberger, and Russell Wilson.

Disclaimer: This second part took so long to produce because I became violently ill after watching so many plays of Aaron Rodgers wearing those horrible yellow uniforms. I am feeling better now, thanks for asking.

There is a lot to digest here. One thing I will say that won’t show up in these videos, is that these quarterbacks did not throw the ball deep as much as Trubisky. Well, at least they didn’t run a designed deep shot from the pocket as much anyway.

What you notice from other quarterbacks are things like back-shoulder throws, off-script deep shots, quick decisions, and perhaps above all else, chemistry with the receivers. Why does the chemistry matter? Those back-shoulder throws are just misses if they haven’t been practiced. A quarterback must know that a receiver is going to come back for the ball when the defender’s back is turned (there is also some luck involved here if you ask me).

The other thing that we see is ball placement, release angle, and velocity. Trubisky’s comp for me coming out of college was Drew Brees. They actually throw the ball very similarly after studying both side-by-side. The problem with this is that Brees is insanely accurate and he can throw pinpoint passes anywhere on the field. As accurate as Trubisky was in college, and at times in the NFL, he isn’t on that level.

What we see here from other quarterbacks is throwing the ball in such a way as to allow your receiver to make a play, or at least put them in the best position to. The first 3 passes from Rodgers illustrate this incredibly well. From the back shoulder throw on the sidelines, to knowing that there is no safety help and leading the receiver over the middle to scrambling to keep the play alive instead of running. I am not ashamed to admit that Rodgers is the best quarterback in the NFL and it’s plays like these that make it so.

Reasons For Optimism

We saw Trubisky demonstrate all of these qualities throughout the season and that makes me excited for next season. It’s about watching film and correcting the mistakes that were made in 2017 and 2018. We saw tremendous growth from week 4 through the shoulder injury, and that is a huge reason to be optimistic. While there was plenty to clean up in that span, there were some incredible throws made as well.

Let’s start with the intermediate throws that were over 15 yards, but under what I would consider a true deep ball.

There is a little bit of everything here. Precision passes, touch throws, back-shoulder, throwing receivers open, and going way off-script. When Trubisky was comfortable and just playing football, he was very good. When Trubisky wasn’t comfortable or unsure of himself, he made mistakes… lots of mistakes.

This is why I have pounded the table be patient until year 2 of Nagy’s offense. All 11 starters are returning (except maybe Howard) and will already know the system. That bodes well for the future and leads us into the next part of Johnathan’s article.

Positive Regression/We’ve Seen it Before

Since deep passing performance is variable, it makes sense to reason that Mitchell Trubisky is due for some positive regression in that area next year. To flesh that hypothesis out a bit more, I looked at seasons where quarterbacks struggled with the deep ball, and how they were followed up.

Trubisky completed 38.5% of his deep passes in 2018. Of the 155 QB seasons I looked up, that number fell below 39% 46 times. In those seasons, quarterbacks averaged completing 34.9% of their deep passes, but the following season saw that rise to 41.2%.

Trubisky saw 8.3% of his deep passes get intercepted in 2018. Of the 155 QB seasons I looked up, that number came in above 8% 22 times. In those seasons, quarterbacks averaged an interception on 9.8% of their throws, but the following season saw that cut by more than half to 4.8%.

There have even been seasons where QBs had a bad year throwing deep in terms of both completion and interception percentages. There have been 10 instances when QBs came in completing less than 39% of their deep balls and getting more than 8% of them intercepted. Their follow-up year saw an average of 43.7% completion and 4.9% interception.

This is where the rubber-meets-the-road as far as the numbers and film matching up together. History tells us that Trubisky will improve simply because he was relatively poor last year. But I look at like this: we have seen him execute deep passes before. Couple that with the fact that there were so many that missed by a matter of inches, there were a few that should have been caught by a certain $14M receiver, and everyone was feeling each other out last year. Those shouldn’t be issues heading into 2019.

What you will notice is what I mentioned earlier about Brees. A lot of these throws are too flat, meaning they didn’t get high enough in the air. A flat throw requires near-perfect placement, which is incredibly difficult. It doesn’t allow the receiver to make a play on the ball, especially if the coverage is good. More air under the ball with a little less velocity, and I think the numbers would improve significantly.

The other thing is the ball placement itself. Trubisky helped the defense out too often by throwing the ball to the outside (sideline side) of the receiver. While it’s true that your chances of an interception lessen with that approach, so does your chances of completing the pass. If you go back and watch Russell Wilson’s touchdown throw in the first video, you see how much room is between the ball and the sideline. It allows your receiver to make a play on the ball instead of giving the defense a 12th defender (the sideline).

All of this is to say that I fully expect, not only the deep ball, but the offense as a whole to improve significantly in 2019. This Bears offense showed enough in short bursts that we know that they are capable of being highly explosive. The next step is showing that consistently. A few tweaks here and there and I think we will see exactly that.

Keep checking back on Da Bears Blog and Windy City Gridiron for more of this fun series!

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