Analysis: Measuring how explosive Notre Dame's offense was in 2018

Chip Long took a question about the ceiling for tight end Cole Kmet and turned it into a tangent about improving Notre Dame’s offense.

The Irish offensive coordinator connected Kmet to dominating the middle of the field, which led to Long commenting on Notre Dame’s receivers inability to break tackles last season.

“The amount of yards we left out there last year is absolutely embarrassing,” Long said March 7 after Notre Dame’s third spring practice. “So being able to get yards after contact is probably one of our No. 1 emphases on offense. We have to be explosive.”

Then Long cited exaggerated numbers to compare the offenses of the 2018 and 2017 teams.

“We had two plays over 50 yards last year and went to the College Football Playoff. That’s very rare,” Long said. “The year before we averaged that a series.”

In reality, the Irish had six plays of at least 50 yards in 2018. The previous season, the offense totaled 12 such plays. But Long’s point was clear. He wants Notre Dame’s offense to make more big plays in 2019.

“I don’t think last year we really scared anybody,” Long said. “There were a couple of games our physicality showed up, but not very consistent and we weren’t explosive. That caught up to us.”

A closer look at the numbers reveals the differences in how explosive the previous two Notre Dame offenses have been. In some ways, the 2018 offense was more explosive.

When comparing plays of 20-plus yards, the 2018 offense actually held a slight 70-62 advantage over 2017. But when you increase the category by 10 yards, the comparison swings in 2017’s favor: 34-30. The 2017 offense also had more plays of 40-plus yards (16-12) and 50-plus yards (12-6 as previously mentioned).

Why did the 2017 team have a more explosive offense? The running game. At four 10-yard increments starting with runs of 20-plus yards, the 2017 offense has the advantage. And the percentage difference widens at each increment: from a 33-21 margin at 20-plus yards to a 23-12 margin at 30-plus yards to a 12-5 margin at 40-plus yards to a 10-3 margin at 50-plus yards.

On the flip side, the 2018 offense was more explosive in the passing game. At the same 10-yard increments starting with passes of 20-plus yards, the 2018 offense has the advantage, though the percentage difference between the two fluctuates between bigger and smaller. It starts with a 49-29 margin in 2018’s favor at 20-plus yards, tightens slightly to 18-11 at 30-plus yards, widens at 40-plus yards to 7-4 and shrinks to a 3-2 margin at 50-plus yards.

The differences between the 2017 and 2018 offenses shouldn’t be too shocking. The 2017 offense had a dominant offensive line and running back Josh Adams ripping off long runs. The 2018 offense still had an explosive Dexter Williams at running back, but the offensive line wasn’t as consistent and Williams missed the first four games of the season.

In the passing game, even though Ian Book had some struggles throwing deep as Notre Dame’s quarterback in 2018, he performed better in his nine starts than Wimbush did in 2017.

As Long mentioned, Book wasn’t relying on yards after the catch to carry his numbers. In Book’s nine starts, he completed 211 of his 311 passes (67.8 percent) for 2,615 yards and 18 touchdowns. According to Tribune film analysis, Book’s receivers accounted for 1,255 yards after the catch. That equates to 5.95 yards per catch and nearly 48 percent of Book’s total passing yardage.

Notre Dame’s pass catchers only surpassed their season average for yards per catch in three of Book’s nine starts: Wake Forest (7.96), Navy (7.15) and USC (8.5).

Book’s 18 touchdown passes thrown in his nine starts were evenly split between receptions caught in the end zone and receptions that required yards after the catch. Only four of the nine touchdowns that required yards after the catch needed more than 10 yards from the receiver to reach the end zone.

But five of the touchdowns that required yards after the catch were made by players returning to Notre Dame’s roster in 2019: wide receivers Chase Claypool (3) and Michael Young (1) and running back Tony Jones Jr.

While the 2018 offense might have been more explosive than Long gave it credit for, there’s still room for improvement. And there’s reason to be hopeful that the passing game can carry that explosion in 2019.

Odds and ends from 2018

• Notre Dame’s offense scored 50 touchdowns in 2018. Five players who won’t be playing for the Irish in 2019 scored 27 of those touchdowns. The other 23 were scored by returning Notre Dame players: running backs Jafar Armstrong (7) and Tony Jones Jr. (4), quarterback Ian Book (4), wide receivers Chase Claypool (4), Chris Finke (2) and Michael Young (1), and tight end Brock Wright (1).

• Notre Dame’s quarterbacks were pressured on 160 of their 505 dropbacks (31.7 percent) in 2018.

• Book completed 71.4 percent of his passes off of play fakes in his nine starts last season. He finished 80-of-112 for 954 yards and six touchdowns with two interceptions on 125 play fakes.

• Book completed all but four of his screen passes thrown in his nine starts. He finished 44-of-48 (91.7 percent) for 327 yards and one touchdown.

• In his nine starts, Book completed only 23.8 percent of his passes thrown 31 yards or more beyond the line of scrimmage. Here’s a complete throwing depth breakdown on Book’s nine starts compiled through Tribune film analysis.

Behind or up to the line of scrimmage: 55-of-59 (93.2 percent) for 394 yards and one touchdown.

1-5 yards: 61-of-82 (74.4) for 552 yards and five touchdowns with one interception.

6-10 yards: 44-of-63 (69.8) for 447 yards and three touchdowns with two interceptions.

11-15 yards: 17-of-35 (48.6) for 310 yards and three touchdowns.

16-20 yards: 17-of-27 (63) for 386 yards and one touchdown with three interceptions.

21-30 yards: 12-of-24 (50) for 317 yards and three touchdowns with one interception.

31-plus yards: 5-of-21 (23.8) for 209 yards and two touchdowns.