Notre Dame By the Numbers at Midseason

No game to review today, so since we're about halfway through the season it's time to take a deep dive into Notre Dame's statistical profile to see what's going great, not so great, and just fine. Most things are pretty great!

For definitions of each metric, check out the glossary here. Most numbers from (and much thanks to) Bill Connelly and the Football Study Hall crew's advanced profiles found here, which are a treasure trove of awesome information on every single team.

Notre Dame Offense

Running the Ball

Rushing Offense	Avg.	Rk	Nat'l Avg.
Rushing S&P+	139.0	2	100.0
Rushing Success Rate	49.5%	16	42.0%
Rushing IsoPPP	1.24	12	1.08
Adj. Line Yards	127.2	10	100.0
Opportunity Rate	50.8%	2	39.1%
Power Success Rate	62.5%	85	67.0%
Stuff Rate	21.2%	91	19.4%

The Irish ground game has been consistently dominant, rankings 2^nd nationally in Rushing S&P+. Maybe the best news here is that the Notre Dame rushing attack has a sustainable balance between efficiency (16^th) and explosive plays (12^th). The only offense in college football that ranks higher is FSU, who has been far less efficient and dependent on Dalvin Cook breaking long runs (which is ok when he's better at that than anyone else).

Qualitative observations that the Notre Dame offense line is one of the best in the nation are backed up by their run blocking numbers - top ten in line yards and opportunity rate, which measure how well blockers are providing easy yardage for runners. This isn't to diminish what CJ Prosise has accomplished - he's been one of the top 10 backs in the country in highlight yards per opportunity, which measures what runners do after taking the yardage the line has given them.  Oh by the way, in limited carries Josh Adams is averaging even more yards per carry (7.8) and highlight yards per opportunity (7.7) than Prosise - he's got a bright future ahead.

Two of these numbers jump out where despite all their running successes, the Irish are below average nationally. Power Success Rate measures conversions on runs in 3^rd and 4^th of two yards to go or less (or less than two yards to go on 1^st and 2^nd and goal). After digging deeper, this doesn't concern me as much - after struggling in these scenarios against UVA (2 of 7) and Georgia Tech (3 of 5), the Irish have improved dramatically in power situations. Over their last three games (Clemson/Navy/USC) Notre Dame is 10 for 10 in power run successes - six of those conversions were runs by DeShone Kizer.

The most confusing number here is the stuff rate - how often an Irish runner has been stopped at or behind the line of scrimmage. Some of this may be a somewhat small sample size and the less important difference between a run for no gain and one yard. But to avoid falling into passing downs on second and third down, this is one small area for improvement.

Passing the Ball

Passing Offense	Avg.	Rk	Nat'l Avg.
Passing S&P+	124.7	17	100.0
Passing Success Rate	46.1%	24	40.4%
Passing IsoPPP	1.58	41	1.48
Adj. Sack Rate	106.8	54	100

The Notre Dame passing offense hasn't suffered at all with DeShone Kizer taking over after Malik Zaire's injury, rating 17^th in the nation. Like the running game, it's been a balance between efficiency and explosiveness, where Will Fuller (21.9 yards per reception) and Chris Brown (13.2) have provided big plays. The passing sack rate is a little high for an elite offensive line, but responsibility for them is divided between the line (mostly excellent but has had some rare miscommunications) and quarterback, where DeShone Kizer has at times held onto the ball too long.

Passing Downs Offense	Avg.	Rk	Nat'l Avg.
Passing Downs S&P+	147.3	1	100.0
Passing Downs Success Rate	40.2%	4	30.1%
Passing Downs IsoPPP	2.20	11	1.80
PD Line Yards per Carry	4.55	7	3.23
PD Sack Rate	9.9%	100	7.2%

This is maybe the most unlikely (and awesome) area of the offenses' success.  This is where coaches worry about inexperienced quarterbacks - on second and third and long, when the defense knows you have to pass, can you make the right play and avoid costly mistakes? And to the credit of DeShone Kizer and the entire offense, Notre Dame is first nationally on passing downs (2^nd and 8+, 3^rd and 5+). To be clear, this also includes runs on passing downs, where Notre Dame has been extremely effective. But passes on third and long have been an area of strength for the Irish thanks to strong patience and decision making by Kizer and good protection by the offensive line.

Notre Dame Defense

Defending the Run

Rushing Defense	Avg.	Rk	Nat'l Avg.
Rushing S&P+	111.3	39	100.0
Rushing Success Rate	38.1%	41	42.0%
Rushing IsoPPP	1.29	121	1.08
Adj. Line Yards	114.6	27	100.0
Opportunity Rate	34.0%	32	39.1%
Power Success Rate	68.4%	78	67.0%
Stuff Rate	22.9%	38	19.4%

The Irish run defense has been far from perfect, but it's significantly improved from 2014. Over the last five games from last season (which didn't include Navy) Notre Dame's opponents rushed for an average of 234 yards on 5 YPC. With the loss of Jarron Jones, improvement from rating in the 70's nationally to a top-40 unit is a solid advancement. Holding opponents to such a low rushing success rate is impressive considering the Irish have faced two option teams that generally are extremely efficient. More good news - the line is not giving opponents many open holes, and a stuff rate in the top-40 is another good indicator of consistent disruption.

The problem is that when opposing offenses have been successful, they've run way too far. It's the same issue that's plagued the passing defense, and many times it's come down to missed assignments, poor tackling, and taking bad angles toward the ball carrier. These are in theory coachable mistakes, but when you're giving up explosive plays this consistently at some point you are what you are - a defense that doesn't bend much but is too often broken for big plays.

Pass Defense

Passing Defense	Avg.	Rk	Nat'l Avg.
Passing S&P+	126.3	18	100.0
Passing Success Rate	34.1%	28	40.4%
Passing IsoPPP	1.69	112	1.48
Adj. Sack Rate	85.7	85	100

This is unexpectedly nice. Despite the trick plays and USC's 400+ yard passing day last week, the Notre Dame pass defense ranks 18^th nationally. They've been stingy in allowing opposing quarterbacks to get going, limiting them to success on only  around a third of all passing plays. Then of course you have the downside - on the rare occasions opponents have found success through the air, those plays have been daggers.

Critics of Brian Van Gorder will over-index on the explosive plays given up. It's extremely valid criticism, but if the passing defense is close to a top-25 unit, does it matter what that looks like? Is there an aesthetic component - that some fans would prefer the bend but don't break Diaco era, which would allow opponents to pass for more efficiently but limit big plays? If you end up in the same place, does it even matter?

More importantly, does this team have the personnel to play bend but don't break? There's not much of a pass rush, in particular without blitzing, as evidenced by the low sack rate. The Irish have talented corners but safeties who struggle in coverage, and I'd imagine that with a lot of time opponents like Deshaun Watson and Cody Kessler could pick the Notre Dame defense apart, even if you're dead set against giving up the big play. IsoPPP is also not an opponent adjusted stat (but IsoPPP+) is coming, and while it still won't be pretty, that should improve the Irish from around last in the country to below average if I had to guess.

Passing Downs Defense	Avg.	Rk	Nat'l Avg.
Passing Downs S&P+	146.8	9	100.0
Passing Downs Success Rate	20.0%	8	30.1%
Passing Downs IsoPPP	2.32	125	1.80
PD Line Yards per Carry	2.30	13	3.23
PD Sack Rate	7.1%	67	7.2%

The Irish actually become a top-10 defense when forcing opponents into passing downs, and their identity remains as consistent as ever in these situations. They've made opposing offenses extremely inefficient in these situations, but allowed the big plays on those rare successes. Still #9 nationally is an impressive overall result.

Special Teams

There's not a lot of advanced metrics here to dive into here - field position is often the biggest impact, which we'll look at in the Five Factors below. New this week is updated FEI ratings, the complement to S&P+ that combine to make F+ (generally the advanced ranking system I lean on most). The results are consistent - FEI rates ND #9 offensively (8^th S&P+) and 36^th defensively (48^th S&P+). Bonus points - FEI does specifically split out special teams' contributions and here Notre Dame ranks 9^th in FBS.

Overall & Five Factors

Category	Offense	Rk	Defense	Rk
S&P+	40.1	8	25.5	48
Points Per Game	38.3	19	22.6	41

		Offense		Defense
	Category	Avg.	Rk	Avg.	Rk	Nat'l Avg.
EXPLOSIVENESS	IsoPPP	1.40	19	1.46	119	1.27
EFFICIENCY	Success Rate	47.9%	19	36.3%	31	40.4%
FIELD POSITION	Avg. FP	30.3	59	26.6	22	29.7
FINISHING DRIVES	Pts. Per Trip in 40	5.15	41	3.95	22	4.68
TURNOVER MARGIN	EXPECTED	0.45	60	Turnover Luck (PPG): -0.32

Looking strictly at the numbers here, I'd say it paints a pretty accurate picture of what I've watched with this Notre Dame team. Their biggest strength is one of the top offenses in the nation (really just significantly trailing Baylor, who is a level above everyone else right now), led by a dominant run game and offensive line. The passing game is also a strength, in particular when penalties or poor performance force the Irish into passing downs.

The defense has been inconsistent, leading to a rank around 40^th nationally (right around Stanford, interestingly enough). The obvious flaw has been the tendency to give up explosive plays, both on the ground and through the air. But the Irish are good at making it difficult for opponents to find efficiency and put together long drives, and when they can force passing downs they've been even better. The pass defense has been stouter than the run defense, but both are significantly improved after a dismal 2014 performance. Notre Dame also benefits from a terrific special teams unit that's helped them consistently gain advantages in field position.

Miscellaneous Investigation

	Offense		Defense
	Avg.	Rk	Avg.	Rk
Q1 S&P+	147.3	5	119.3	24
Q2 S&P+	103.4	80	116.9	35
Q3 S&P+	157.4	1	125.9	28
Q4 S&P+	142.8	2	110.9	46
1st Down S&P+	131.0	7	111.0	36
2nd Down S&P+	129.0	14	127.8	15
3rd Down S&P+	141.8	7	135.7	14

One question I wanted to specifically look at was 2^nd quarter performance - any specific reason opponents have been able to be more successful in those 15 minutes? The Irish have a point differential of +110 through seven games, but are -13 in Q2. What gives?

The breakdown of S&P+ clearly shows that the outlier here is the offense, not the defense. For some reason this unit that has been consistently great has struggled in the second quarter - which seems like a random time, since it's not post halftime adjustments (if you really believe in those) and slow starts in the first quarter seem easier to explain. Upon further examination, the struggles have been evenly divided between the passing and ground game.

Running the ball, Notre Dame averages 5.95 YPC, but just 4.36 in the 2^nd quarter. Kizer's passer rating is its lowest of any quarter, with 3 TDs and 3 interceptions. He's also thrown the ball more than in the second than any other quarter -2-minute drills could be a factor, but he has 59 passing attempts in the 2^nd and no more than 35 in any other quarter. The other big factor here is turnovers - the Irish have lost five of their nine turnovers in the second period of play. That goes a long way in explaining the negative scoring margin, but the increased difficulty moving the ball remains mostly a mystery to me. Maybe Notre Dame needs to keep running the dang ball more then? That's always a preferred armchair quarterback solution, so that'll be my final recommendation.

There were a few other questions I wanted to look into, included opponents success rates when Notre Dame blitzes or doesn't, and how DeShone Kizer rates at passes to different parts of the field. Even with my OFD Premium passwords I couldn't find good data sources, but if anyone knows of a good database to find some of those answers I'll include next week.