Mizzou’s defense had a strange relationship with penalties in 2017

By the end of 2017, Missouri’s defense was pretty darn good. Granted, it didn’t face just a ton of elite competition down the stretch, but the Tigers still held most of their opponents below season averages over the second half of the year.

• Idaho: 5.1 yards per play for the season, 3.8 against Missouri
• UConn: 5.5 for the season, 3.8 against Missouri
• Florida: 5.2 for the season, 5.8 against Missouri, BUT at 16 points, the Gators were six below their season average in that category
• Tennessee: 4.8 for the season, 4.2 against Missouri
• Vanderbilt: 5.6 for the season, 4.9 against Missouri
• Arkansas: yeah this one was pretty bad
• Texas: 5.2 for the season, 3.9 against Missouri

So after the debacle that was the Georgia game (and most of the games before that), Missouri held five of its last seven opponents well below their season per-play averages.

Full-season averages, therefore, aren’t incredibly helpful. Per my S&P+, Mizzou’s average defensive percentile performance was 26% during its 1-5 start and 71% during its 6-1 finish.

The difference was primarily in the efficiency category. When Mizzou suffered a glitch, it was an enormous one, but there were simply far fewer glitches.

IsoPPP is my explosiveness measure of choice. It measures the magnitude of your (or your opponent’s) successful plays and allows me to break everything down into two questions: “How frequently were successful?” and “When you were successful, how successful were you?” Mizzou improved in the former, but the latter was still problematic. The Tigers finished the year 117th in rushing IsoPPP, 117th in passing IsoPPP, and 130th -- dead last -- in passing downs IsoPPP. Mizzou had an okay pass rush (something else that improved down the stretch) and made a ton of plays behind the line of scrimmage against the run (seventh in stuff rate), but when there was a breakdown, it was catastrophic. (You know this, of course. You saw the Missouri State game.)

Per ESPN’s David Hale, though, we do see another issue Missouri had from time to time: penalties.

As a rule, I don’t do anything with penalties for S&P+ because including them doesn’t do anything for my measure’s predictiveness. They’re pretty random — 119 of FBS teams averaged between one and two penalties per quarter, which is a drop in the bucket, really — and as Hale notes, the teams that commit the fewest penalties often aren’t being aggressive enough to win games.

Plus, not all penalties are created equal; procedural penalties are a bad sign at basically all, but things like personal fouls or maybe pass interference penalties or other things can, again, be a sign of worthy aggressiveness.

Still, this was interesting enough for me to look into a bit. What I found was a defense that Mizzou’s relationship with penalties changed pretty dramatically as its defense improved.

What’s funny is, if you break the season into two chunks — the 1-5 start and the 6-1 finish — Mizzou allowed the same average points in penalty drives (2.8) and really averaged the same number of penalty-free drives per game (10.7 in the first six games, 10.0 in the last seven). The improvement came within the penalty-free drives themselves: 3.2 points per possession in the first six games, 1.1 per possession in the last seven.

But if we home in a little further, we see there were really three acts to this play.

• First 6 games: During the Tigers’ 1-5 start, penalties meant nothing. They allowed 3.2 points per possession when not committing a penalty and 2.8 per possession when committing at least one. Basically, committing a penalty was a good thing, I guess because of what I mentioned about aggressiveness above.
• Next 4 games: Against by far the weakest offensive opponents on the schedule (Idaho, UConn, Florida, Tennessee), something interesting happened. Sure, Mizzou’s defensive averages improved as you would expect, but suddenly opponents desperately needed penalties for points: they averaged just 0.8 points per possession when Mizzou didn’t commit one and 1.9 per possession when they did.
• Last 3 games: Starting with basically the second half of the Vanderbilt game, Mizzou’s defense got a little too loose. As you’ll recall, Mizzou allowed 21 points against Vandy in the second half (after pitching a shutout in the first), then gave up 45 to Arkansas and committed three penalties on Texas’ game-opening touchdown drive in the Texas Bowl. The Tigers stabilized from there against Texas, but at this point, penalties were a pretty bad thing. In these three games as a whole, Mizzou allowed just 44 points in 32 possessions without a penalty (1.4 per drive) but 44 in 11 drives with at least one (4.0).

Aggressiveness looked pretty good on Missouri, especially as players like Marcell Frazier (three tackles for loss in the first six games, 12.5 in the last seven), Terry Beckner Jr. (two TFLs in the first six, nine in the last seven), and Adam Sparks (took over for Logan Cheadle as starting cornerback midway through the year) found their respective footing. And corner Demarkus Acy, a homing beacon for yellow flags, got himself under control a bit as the season went on as well.

Still, toward the end of the year, after a dominant four-game span against mostly bad offenses, there were enough glitches and volatility to warrant a wee bit of concern.

Granted, you’d still take the late-season defensive performance over that of the early season. But if Mizzou’s going to reach its newly-increased over-under win total (it’s 7.5, up from 6.5 a few weeks ago), let’s make sure those volatile drives still remain in the “two to three per game” range.