A closer look at the 2021 Notre Dame stop rate
This article originally appeared in the Blue & Gold Illustrated recruiting magazine that covered the 2022 class. Click here to order your copy!
When discussing defensive success in football, metrics such as points and yards allowed are frequently tossed around as measures of competency. The problem? Those statistics do not tell the full story, especially in today’s college football.
Instead, Max Olson of The Athletic uses a team’s stop rate to explain defensive success, and he released the final stop rate standings following the conclusion of the 2021 football season.
Olson defines the stop rate as “the percentage of a defense’s drives that end in punts, turnovers or a turnover on downs.” The measure exists to provide clarity concerning a defense’s effectiveness in a college football world where offensive schemes are rapidly changing and becoming more high-powered. If a drive ends without points, it is considered a success at the end of the day.
In 2021, Notre Dame came in at No. 17 with a 72.5 percent stop rate. The national champion Georgia Bulldogs led the nation with an 83.4 percent stop rate, and fellow College Football Playoff teams Michigan (75.3 percent) and Cincinnati (75.2 percent) sat in the No. 8 and 9 spots, respectively.
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The only team that made the CFP listed outside of the top 10 was Alabama. The Crimson Tide finished No. 19 with a stop rate of 71.7 percent.
How did Notre Dame end up at 72.5 percent?
Here is a deeper look at how most of the Irish defensive drives ended in 2021.
The Irish forced 10 fumbles and intercepted 15 balls over the course of last season, while giving the football away on 16 occasions. Their +9 turnover margin was tied for 15th in the nation.
They also put their opponents in a high number of third down situations; Notre Dame tied for 25th nationally with 184 forced third downs in 2021. Opponents converted just 31 percent of those attempts, often due to yardage losses on previous plays putting opponents in third-and-long situations. Obviously, when the opponent can’t convert easily, they are often stuck with a fourth down.
However, when the opponent did elect to go for it on fourth down, Notre Dame’s fourth down defense was less impressive. Opponents tried to convert on 16 fourth downs over 13 games, and the Irish allowed the conversion on nine of them. The .562 opponent success rate was No. 82 nationally. This is a smaller sample size and not too alarming, but it is a data point worth mentioning.
All in all, Notre Dame’s 11-2 season featured an above average defense, as is evidenced by a No. 17 stop rate ranking. But a stop rate around 80% could take the team to a new level, perhaps one involving a national championship.
