Notre Dame Fighting Irish VS North Carolina Tar Heels: Analytics Recap

Notre Dame solidified themselves as one of the nation’s best teams last Friday, passing their most difficult remaining regular season test with flying colors in a 31-17 victory over then No. 19 North Carolina Tar Heels. While the Irish offense had no turnovers and had positive EPA/play both when rushing and passing, the defense was the story. Clark Lea’s group gave up touchdowns on the first two drives of the game, and then gave up three points the rest of the way including zero points allowed in a second half played without Kyle Hamliton. This Irish squad is a legitimate national title contender, and we have the stats to prove it. For a primer on the statistics we will be using, please follow this link to our analytics primer.

This may have been the greatest defensive performance in a game by any team this season. Notre Dame completely took away North Carolina’s vaunted rushing attack. The Tar Heels had the second best rushing game in the country pre-game, averaging 0.24 EPA/Rush with lead back Jevonte Williams averaging a ridiculous 0.39 EPA/rush. The Irish held Williams to a putrid -0.59 EPA/rush in this game, with UNC’s running game as a whole at -0.28 EPA/Rush. After seeing this run defense operate against Clemson and UNC, it’s become clear that this is a matchup proof run defense. Clark Lea’s front seven will be ready to face anyone, and as long as they finish tackles (which was an issue early in the game) no one can expect to generate positive EPA on the ground against this group.

While stopping the run was great, we predicted in our preview that North Carolina’s success on offense would go as Sam Howell went. This turned out to be completely true. The Tar Heels moved the ball well in the first half, scoring 17 points while generating 0.58 EPA/Dropback. All seemed lost when Kyle Hamilton was ejected and the UNC offense was poised to put up points in bunches, but Clark Lea worked another miracle. Safeties Houston Griffith and DJ Brown stepped up in a big way to fill Hamilton’s shoes as the Irish pitched a shutout in the second half. They limited the once potent North Carolina passing offense to 2.6 yards/Dropback in the second half, too low to put even a single point on the board. For an excellent look into how Clark Lea schemed up the defense to shut down North Carolina’s Run-Pass Option (RPO) game, check out Seth Galina’s article on PFF.

The pass rush was key to making this happen, as we predicted. The Irish generated six sacks, and could have had more if they did a better job wrapping Howell up in the first quarter. Howell was under pressure on 47% of his dropbacks, disrupting Howell’s timing and resulting in him throwing over 20 yards down the field just once because his receivers did not have time to get down the field. Notre Dame accomplished this while only blitzing on 22% of his dropbacks (8 times). Howell threw over 20 yards down the field on 19% of his throws entering Saturday, but did it just once on 27 attempts Saturday. The secondary deserves credit as well, but it was the defensive line that generated pressure and made Howell uncomfortable.

It is worth noting that Notre Dame was stout against play action in this game (Note: we don’t make a distinction between RPO and play action plays). This is great to see since stopping the run against Clemson and Boston College came at the expense of conceding big gains to play action. If Clark Lea can figure out how to repeat stopping the run without overcommitting defenders to it it will be very difficult to score points on this defense.

The Irish generated positive EPA on the ground for the first time since the Louisville game, with their team 0.11 EPA/Rush their highest since the Florida State game. Kyren Williams was better individually than his -0.01 EPA/Rush shows, as he was met in the backfield several times and able to make athletic plays to spin out of trouble. His PFF rushing grade was above 80 on the day, showing the lack of success on the ground was not his fault and more due to Tommy Rees calling run plays into loaded boxes. The rushing attack has the potential to be elite, but there needs to be a change in mindset from Rees. The Irish need to spread to run in order to both give Williams space to operate and reduce the number of defenders the offensive line has to block.

Despite a better day from the run game, Ian Book is still the reason the Irish offense moves. He averaged 0.27 EPA/drop back in a game where he faced constant pressure. Zeke Correll struggled in his first game at center, rolling back several snaps and finishing with a Pro Football Focus Pass Block grade of 16. This led to 32.3% of Book’s throws coming from outside the pocket, far higher than his season average of 21.7%. Book was able to generate positive EPA on these plays that could have been even higher if not for a first half Michael Mayer drop and Ben Skowronek just barely being ruled out along the sideline in the second half. While Ian Book does look great delivering throws outside the pocket, it is important to remember he is still far more productive when he stays in the pocket. The Irish offensive line was admirable given the circumstances of playing without Patterson and Kraemer, but Patterson is not coming back and the Irish need to raise their play from the center position.

Avery Davis and Tommy Tremble drew the short straws this week, with most of the passing offense running through Javon McKinley, Michael Mayer, and Ben Skowronek. Javon McKinley is an absolute star for this Irish offense. Book appears to trust him more each week, and McKinley keeps rewarding him for it. Book threw McKinley a deep jump ball which Javon rose up to secure directly over a Tar Heel defender. McKinley’s emergence has answered most of the questions surrounding Irish passing, but Tommy Tremble’s role in the passing game is now uncertain. Tremble is well-known as a dominant blocker, but he posted another drop and only caught one pass for almost no gain following the Boston College game where he was not targeted once. As Michael Mayer continues to bud into a superstar, one has to wonder how much volume is going to be left for Tremble.

The sample sizes are getting larger for motion stats and it is becoming clear that Notre Dame is better when they run motion. At the snap motion has been the most efficient play type in three straight games, and has not resulted in negative EPA for a full game since Pittsburgh. If the Irish want to keep introducing new wrinkles to the offense in the stretch run, more plays that involve misdirection may be a start.

In addition to snap motion, play action torched the Tar Heels. The Irish went through a mid-season stretch where play action was less efficient, but that is mostly just noise given what we know about the added efficiency of run fakes. The Irish have been more efficient running play action than straight drop backs in three straight games and the season overall. Notre Dame ran play action 27.8% of the time in this game, and we would like to see this increase even further to above 30% in the games to come. If the Irish continue to Let Book Cook, run motion and play action, and spread to run, this offense could get even scarier than it is right now.