Wrapping up the advanced stats from Notre Dame’s regular season with an eye toward Clemson – how can the Irish move the ball on the nation’s top defense? The numbers provide strong evidence that it’s time for Ian Book to really air it out.
Irish Run Offense vs. Clemson Run Defense
Running into an orange wall
One of the biggest stories of the offseason was Clemson’s monstrous defensive line of potential 1st Round NFL picks all choosing to return for 2018. Junior Dexter Lawrence was the only one without an option to return, but Clelin Ferrell and Christian Wilkins seemed locks to last at longest until early in the second round and chose to come back to play for Dabo Swinney and Brent Venables for one more year. Austin Bryant’s stock was maybe a touch lower that the rest of the trio, but he was coming off a junior season with 15.5 TFL, 8.5 sacks, and a pick.
It’s been the rare winter storyline that has lived entirely up the hype – the Tigers were the top defense in the nation per S&P+ and 3rd in FEI. The defensive line, as expected, has fueled that dominance, leading the nation in opponent yards per rush, Rushing S&P+, opponent run explosiveness, and line yards allowed per carry on both standard and passing downs. Clemson is 3rd in run stuff rate, stopping 27% of opponent runs for no gain or a loss.
The vaunted line leads FBS in DL havoc rate, with a 10.9% havoc rate just as a unit that is more than double the national average (5.0%) and more than a handful of FBS defenses as a whole (including Louisville, who was dead last in FBS in the category – hey, Brian Van Gorder). They’ve managed to be this incredibly disruptive without giving up big plays either – the Tigers have yielded just four rushes of 30 yards or more, a top-10 figure nationally and tied with Notre Dame. Without factoring in garbage time, which was substantial in a weak ACC, only four of Clemson’s 13 opponents managed over three yards per carry, and not a single one broke four yards per rush.
An explosive yet inconsistent Irish run game
Meanwhile, the major weaknesses in Notre Dame’s profile is the run game. Following the loss of Josh Adams, Quenton Nelson, and Mike McGlinchey to the NFL (where they are all currently starting, and playing well), the running attack took a major step back to 74th in Rushing S&P+. The major cause? Inefficiency and a lack of consistent success running the ball, caused in part by excessive stuffed runs for no gain or a loss.
The Notre Dame running attack generated above-average efficiency just four times this season, in games against weaker defenses in Vanderbilt (70th in Defensive S&P+), Wake Forest (78th), Navy (120th), and Florida State (a decent 41st). For the entire season the Irish finished a ghastly 95th in marginal rushing efficiency, and you can see a bit of decline after the Stanford game when Alex Bars was lost for the season.
Not only was the efficiency poor, but those unsuccessful runs were also more damaging for Notre Dame than most teams. The Irish allowed a ton of run stuffs and tackles for a loss, especially over the second half, where three of the final four opponents had stuff rates near or above 30% (a number which is better than any FBS team this season). Some of that is scheme, sure, but if Northwestern, Syracuse, and USC are keeping you from positive yardage on around a third of your runs, what will Clemson’s front seven do?
For the season Notre Dame finished 118th in run staff rate allowed, and 116th in opportunity rate, the percentage of carries where the offensive line produces at least five yards of room for the runner. The bright spot? Notre Dame finished 58th in marginal explosiveness, a statistic that increased dramatically when Dexter Williams returned against Stanford after an initial suspension. After the Virginia Tech game this year I compared Williams’ long runs to a seismograph – sooner or later, you knew a tremor was coming and then a full-on earthquake of a long run. I’ve updated the visual now through the end of the season, and raised the bar on my MS Paint and Powerpoint graphics skills:
Runs seem destined for inefficiency
The combination of Clemson’s penetrating run defense and Notre Dame’s inefficiency on offense doesn’t bode well for the Cotton Bowl. It’s probably the single biggest mismatch thinking about each run and pass attack versus either team’s defense. Not only will it be difficult to run efficiently, it’s also likely that many runs also won’t gain much if anything, landing Ian Book in obvious passing situations where Clemson’s pressure and pass rush can really be let loose.
Chip Long has been creative all season, and hopefully that innovation continues against a stellar defense. Notre Dame may benefit from a bit more of a pass-heavy attack than they’ve shown this season – despite Ian Book’s accuracy and efficiency, the run-pass balance has been nearly a 50/50 split in competitive time as a whole and on first downs. When the Irish do run, they should keep the Tigers off balance with misdirection and lots of runners to account for – some keepers for Book, jet sweeps with Chris Finke, and reads that can take at least one elite Tiger lineman out of a play.
The Irish should also be smart with the formations and personnel groupings they run out of – even in red zone and 3rd and short situations, utilizing multiple WR sets to spread out the Tiger front. It’s going to be difficult to open up run lanes against Venables group of mutants no matter what, but the difficulty only grows if heavy personnel packages allow the defense to put 9-10 guys in the box.
Irish Pass Offense vs. Clemson Pass Defense
A weaker piece of the Tiger defense….that’s still easily a top-10 unit
The Clemson pass defense enters the playoffs ranked 6th in Passing S&P+ defense, with many dominant performances but unlike the run defense, a couple of occasions where the Tigers were exploited. Still, the defensive line is still an issue (6th in adjusted sack rate), and opponents have been held to the 12th lowest pass efficiency and 16th lowest pass explosiveness.
The only weaknesses in their profile is that the Tigers have let up a few big passes – 5 of 50+ yards, and don’t get their hands on many passes, ranking just 92nd in pass breakups per game. Still, opponents are only completing 52.8% of their passes (9th nationally), so maybe the lack of deflections is due in part to lots of throwaways and passes way off because of the pressure Venables likes to bring.
The games that should give Irish fans hope against the nation’s top defense are Clemson’s matchups with Texas A&M in Week 2 and against South Carolina the final week of the regular season. Both teams were extremely pass heavy – A&M had 44 pass plays, averaging 9.7 yards per attempt (including sacks), and South Carolina’s Jake Bentley had 50 pass dropbacks and averaged 9.25 yards per pass play. Not coincidentally, those were two of the three best offenses per S&P+ the Tigers faced – the Aggies checking in at 19th, and Gamecocks at 29th.
Still, those performances have been the exception rather than the rule. In last week’s ACC Championship game, Pittsburgh actually had negative yards per pass play – the Panthers sack yardage lost exceeded the pass yardage gained! NC State, a passing attack S&P+respects (13th nationally), managed just 5.5 yards per attempt with no touchdowns and two picks.
A newfound strength for the ND offense – pass efficiency
Entering the season, Irish fans were trying to piece together formulas for an effective offense with the assumption that the passing game would probably remain pretty inefficient. I’d be rich if I had a nickel for every offseason thread or debate I encountered speculating if Brandon Wimbush could raise his completion percentage to 55 or 58%. The surprise of the season was the emergence of Ian Book, and with it a hyper-efficient pass attack that changed the identity of the Notre Dame offense.
It’s a stark contrast looking at Notre Dame’s pass success rates over the past two seasons before and after Book’s ascent to QB1. Despite four games of average and in some games below average pass efficiency with Wimbush starting, the ND offense finished 21st in Passing S&P+ and 15th in marginal pass efficiency. Book’s generally quick decision and solid pass protection from Jeff Quinn’s crew also led to a strong finish limiting opponents sacks, finishing 33rd in adjusted sack rate, including 12th on passing downs.
The passing game hasn’t been quite as explosive, checking in at 54th in marginal pass explosiveness, and if Book has flashed any weakness it’s been deep accuracy. Chase Claypool and Miles Boykin have been reliable weapons with high efficiency and catch rates, but neither are burners downfield and the longest reception between them in 2018 is a 40-yard catch by Boykin. That wasn’t exactly a big downfield play either – it was the catch off a Book scramble at Virginia Tech where Boykin’s defender left him and the senior rumbled in from about 27 yards out after the catch for a score).
Expect Clemson to continue the strategy recent opponents have employed against Book – trying to confuse him with blitzers, dropping ends into coverage, and daring Book to connect with Notre Dame receivers downfield. Boykin, Claypool, Alize Mack, and Chris Finke will have to win contested balls in one-on-one situations, and probably break a big play or two.
Time to air it out
In addition to the Tigers having a slightly weaker pass defense, Notre Dame has been consistently better passing the ball than running since Book took over at Wake Forest. No matter which way you slice it – efficiency, explosiveness, situational stats – the pass game has clearly had an advantage. Despite this edge, after removing garbage time, the Irish have only passed it about 52% of the time versus 48% runs. On standard downs and 1st downs it’s a similar story – nearly 50/50. But should it be?
That’s some pretty strong evidence in favor of airing it out more – regardless of opponent – and with Clemson’s dominant run defense, all the more reason to chuck it around. Notre Dame fans may bristle at that idea – but there’s increasing evidence that a lot of the traditional arguments about running the ball aren’t backed up by data. At the NFL level at least, ideas like “you need to run to set up play action!” haven’t borne out, and I would expect the same to hold true at the college level (play-action is good and effective regardless of how often/well you run).