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A Deeper Dive into the Sophomore Season of Mitchell Trubisky

| February 4th, 2019

After a rookie campaign that was statistically a nightmare, Mitchell Trubisky took the sophomore jump that many wanted to see. He went from performing like one of the worst QBs in the NFL to somebody who was average to above average, and accordingly the Bears went from being one of the worst teams in the NFL to one of the best (though a greatly improved defense also played a big role there).

Now that the dust has settled a little bit, I wanted to take a closer look at Trubisky’s 2018 season to see what I could learn. (I’ll note that I have upcoming work looking in more detail at short and deep splits, so I’m not going to focus on that here.)


Breaking Out

For the first three weeks of the season, Trubisky looked like he was continuing his rookie year. At that point, it was starting to look like maybe the Bears had a bust. Then Trubisky had a monster game against Tampa Bay in Week 4 and never looked back. The distinct split in his performance can be seen clearly in the table below.

A few thoughts:

  • There’s no way around saying it: Trubisky stunk the first three weeks. He dumped the ball out faster than any QB in the NFL, threw it shorter than all but nine, and completed shorter passes than any other QB by a full half yard. Despite all of that, he still threw into tight coverage at the 6th highest rate of any NFL QB this year, and took a high rate of sacks, which were largely on him.
  • But look at Week 4 and on. He started pushing the ball down the field more, which hurt his completion percentage a bit but helped him everywhere else. His full stat line from Week 4 on: 217/330 for 2632 yards, with 22 touchdowns, 9 interceptions, and a 101.0 passer rating. That’s borderline top 10 quarterback production.

Shifting Styles

But Trubisky’s play didn’t remain stagnant for the rest of the season. Instead, we saw a distinct shift in playing styles over the last three weeks of the year, which can be clearly seen in the table below.

A few thoughts:

  • Look at those middle weeks. Trubisky chucked it deep a lot there, as his average pass traveled 9.8 yards past the line of scrimmage, which would have ranked fourth in the NFL. Because of the deep passes, he threw a lot of touchdowns, but also interceptions. Still, his sack rate plummeted from when he was throwing quick, short stuff (the first three weeks) indicating he was getting more comfortable in the offense, and he was able to use his legs as a weapon.
  • Notice that the playing style for the last 3 weeks reverted somewhat back to the first three? He got the ball out fast, threw it short, and accordingly completed a lot of passes. Did the injury play a role here?
  • But now notice what improved from the first three weeks to the last three: his average completion increased by over 2 yards, his completion percentage jumped by a good bit, and accordingly his yards/attempt was still really good. He also didn’t take sacks or turn the ball over, and he threw touchdowns at a more acceptable rate (NFL average is typically somewhere around 4-4.5%). This shows how much he had grown mentally within the offense; early in the year he threw quick and short with no idea what he was doing, but late in the year he was doing it deliberately to play complementary football.
  • Notice that Trubisky also stopped using his legs down the stretch too. He switched from being a bombs-away scrambler who throws plenty of touchdowns and interceptions (think Josh Allen) to an efficient, conservative QB who manages games and lets his defense win (think Alex Smith).

So where does the right balance land for Trubisky?

As I’ll talk more about in upcoming articles, I think he needs to throw it deep a little less than he did in 2018, especially in the middle part of the season. But I think the last few weeks were probably a bit too conservative. Still, he proved in different parts of this season that he can execute both styles effectively, and that’s valuable. Hopefully he (and Matt Nagy as the play caller) can find the right balance of aggressive and efficient to maximize Chicago’s offense going forward.


Historical Context

Finally, I wanted to put Trubisky’s rookie season in a little bit of historical context, based on his statistical production. This can be difficult to do because of how much passing stats have changed over time, but thankfully Pro Football Reference has a nice tool for that with their advanced passing stats. These rank a QB in a variety of stats relative to their peers that season, which allows you to compare between eras a little more effectively. All stats are scaled such that 100 is average, and higher numbers are better.

Here are Trubisky’s advanced passing stats (from his page):

All of his 2018 numbers, except interception percentage, are better than average. That’s very good to see for a quarterback who is only in his second season in the NFL.

To try and put this in some historical context, I used the Pro Football Reference player season finder to look for other young QBs who had similar success relative to their peers in their 2nd year in the NFL.

Since search criteria were limited, I looked for QBs who were 25 and younger, in their 2nd season in the NFL, started at least 10 games, and had a 105 or better in net yards per attempt, completion percentage, and touchdown percentage. Aside from Trubisky, there were only 11 additional names: Pat Mahomes (2018), Dan Marino (1984), Daunte Culpepper (2000), Boomer Esiason (1985), Nick Foles (2013), Peyton Manning (1999), Deshaun Watson (2018), Russell Wilson (2013), Ken O’Brien (1985), Ben Roethlisberger (2005) and Pat Haden (1977).

That’s pretty good company to be in. Not all of those guys went on to be stars, but every player on that list made at least one Pro Bowl, and all of them were solid NFL starters or better. Also: note that all three 2017 QBs are on that list. Maybe we should stop complaining about which one the Bears should have drafted and instead appreciate that all three are pretty good?

This isn’t to say that Trubisky is going to be a great quarterback. We don’t know if that is the case – in either direction – yet. But we have seen enough to say fairly certainly he is at least a good one, and that’s something.

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