What Happened to the Pass Rush?

Courtesy Bloom Magazine

There is no doubt that Coach Allen has reset expectations for the IU defense. In his first two seasons as IU’s defensive coordinator, he molded a defense that previously struggled (and often failed) to attain mediocrity and turned it into an above-average B1G unit. His 2016 and 2017 defenses finished 20th and 25th in Defensive S&P+ respectively.

But something happened in 2018, Allen’s second season as IU’s head coach and third as DC. IU slipped to 75th in Defensive S&P+ – still better than many of IU’s defenses in the last few decades, but far below the standard Allen himself had set. Today we’ll look at one possible cause of that slide: an ineffective pass rush.

IU’s S&P+ ranks reveal a considerable drop-off against the pass: IU finished 104th in Passing Defense S&P+ in 2018, down from 29th in 2017 and 73rd in 2016. On passing downs, IU dropped to 106th all the way from 7th in 2017 and 67th in 2016. So yeah, something definitely went wrong here.

Before we dive into the charts, a quick reminder: in comparing counting stats between seasons, keep this in mind, as I explained last season:

Each season is different in terms of how much usable, non-garbage time data is created. The main reason is obviously that certain seasons feature more blowouts for and against IU than others, and we do not include data from garbage time1in our stats. Additionally, any games against FCS opponents are excluded – generally not an issue but the canceled FIU game and Charleston Southern replacement brought it back in 2017. And of course, some seasons involve bowl games and others don’t.2

So in 2016, we had 12.5 games of usable data, but only 9 games in 2017. In 2018, we had about 10 and 3/4 games of usable data, or an increase of 16% over 2017. As you compare counting stats between the seasons (obviously rate stats would not be impacted) keep in mind that a performance level that remained constant between 2017 and 2018 would produce 16% more in 2018.

Also, keep in mind that this data is compiled by a human (me!) watching (and re-watching) the games and keeping a log. Pressures, missed tackles, etc. are not tracked otherwise.3 While I strive for 100% accuracy, the data you see should be considered an approximation, rather than a perfect and complete data set.

Team Pass Rushing Charts

The charts below show 2016, 2017 and 2018 team pass rushing data. The charts on the left show the IU defense’s results depending on the number of pass rushers used, while the chart on the right shows pass rushing results for specific blitzes.

The major takeaway: IU’s 2018 pressure percentage dropped to 22% from 29% in 2016 and 2017. The means that IU notched a hurry, knockdown or sack on a little more than 1 of every 5 dropbacks, instead of 1 of every 3.5. That may not seem like much, but in a game with 40 dropbacks, those percentages equate to about 3 more pressures. Quite a few good things can happen for a defense with 3 more pressures.

Interestingly, IU blitzed roughly the same amount in 2018 as 2017 (41% to 42%), but IU’s 2018 blitzes were less effective, resulting in pressures only 27% of the time in 2018 as opposed to 32% in 2018. In 2016, by comparison, IU blitzed more – 49% – and had more success when they did – 39% pressure on blitzes. The numbers suggest that IU needed to blitz in 2016 to generate pressure – only a 17% pressure rate on 4-man rushes – and when Coach Allen brought just one more rusher, he more than doubled his pressure % to 36%. In 2018, IU once again needed to blitz to get pressure, tallying only an 18% pressure rate on 4-man rushes, but this time, blitzing only netted an increase to 27% pressure. As a result, Allen (rightfully, one might argue) didn’t really turn up the number of blitzes.

On the specific blitz front, IU’s preferred blitz has remained 4 DL, MLB in all three seasons of Allen’s tenure.4 In 2018, the effectiveness of that blitz cratered, down to 18% pressure rate from 46% in 2017 and 39% in 2016. On the other hand, 4 DL, Husky was a fairly popular blitz, but it’s remained relatively ineffective throughout – 25% in ’16, 17% in ’17 and 21% in ’18. Combining the two (sort of), the 3 DL, MLB, Husky blitz was reasonably effective in 2018 at 35%, up from 33% in ’17. For some reason, the coaching staff dialed back the 3 DL, MLB, WLB blitz in 2018, calling it only 5 times, even though it generated pressure on 4 of those 5 dropbacks. In 2017 and 2016, that blitz was used 18 and 24 times respectively.

Individual Pass Rushing Charts

Turning to the individual pass rushers, the “% Returning” field in the 2017 chart should have tipped us off that the IU defense might suffer a pass rushing dip in 2018. Only 29% of 2017’s pressures returned for last season. And 11 of those returning pressures came from Jacob Robinson, who barely played in 2018 due to injury and only tallied one pressure. On the other hand, the 2018 defense was expected to benefit from the return of Nile Sykes, who missed all of 2017 with an injury.

Sykes’ return helped – he ended up leading the team in pressures – he never really emerged as a true pass rushing threat. The other usual starting DE, Gavin Everett, was even less effective as a pass rusher, tallying just 7 pressures for a total of 18 pressures from IU’s starting DEs. By contrast, in 2017, IU’s starting DE pair of Robert McCray and Greg Gooch put up 30 pressures combined. Similarly, in 2016, IU’s starting LBs Tegray Scales and Marcus Oliver totaled 30 pressures. In 2018, IU’s top LB pair of Dameon Willis and Raekwon Jones put up just 15. IU probably doesn’t need a dynamic DE pair AND good blitzing LBs to have a respectable pass rush, but in 2018, the defense suffered because it didn’t have either.

But there’s hope! First of all, IU returns more than 60% of last season’s pressures, so the defense won’t have to overcome massive turnover like last season. At DE, James Head seems poised to take a big step forward in his sophomore year. I will be very surprised if he doesn’t put up double-digit pressures. Likewise, redshirt sophomore Lance Bryant has earned praise from the coaching staff for his fall camp, and he could make a big jump from the zero pressures he generated last year in limited duty. Allen Stallings has looked like a natural (if undersized) pass rusher at times during his IU career, and he could put together a strong senior season. At DT, Jerome Johnson may be the best overall player on the defense. Whether he generates more pressures for himself or simply attracts attention from opposing O-linemen, his presence should help the pass rush. At linebacker, if Cam Jones and Micah McFadden are consistently deployed in passing situations (as McFadden was at times in 2018) their athleticism alone should lead to pressures – and bringing them on the blitz together (see 3 DL, MLB, WLB blitz above) would be hard for an O-line to handle. In general, because Coach Allen and new DC Kane Wommack prefer to rotate a bunch of guys on defense, we may see an improved pass rush without any one player averaging more than a pressure per game.

In sum, it is entirely possible that the IU defense could jump back up to the 29% pressure range in 2019. Doing so will go a long way towards restoring this unit to a top 40 S&P+ level or better.

  1. Defined as when the game is not within 28 points in the first quarter, 24 in the second, 21 in the third, or 16 in the fourth.
  2. Like when a team can’t hold a 9-pt lead against a terrible Maryland team playing its 3rdstring QB, and thereby costs itself a 6th win. Speaking only in generalities here.
  3. With the possible exception of Pro Football Focus, but most of their data is behind a pay-wall.
  4. As I’ve noted before, I’m focusing strictly on personnel in categorizing these blitzes. I have no doubt that there are many variations on blitzes involving 4 d-linemen and the middle linebacker.