College football defensive stop rate ahead of Week 11

Josh Heupel has earned a well-deserved reputation as one of college football's best offensive masterminds over the past decade. But four years into his tenure at Tennessee, he has built up a defense that just might be the best in the country.

There are plenty of stats you can point to for justifying that claim, but here's one worth considering: The Volunteers rank No. 1 nationally in stop rate for the second week in a row.

What is stop rate? It's a basic measurement of success: the percentage of a defense's drives that end in punts, turnovers or a turnover on downs. Defensive coordinators have the same goal regardless of their scheme, opponent or conference: prevent points and get off the field. Stop rate is a simple metric but can offer a good reflection of a defense's effectiveness on a per-drive basis in today's faster-tempo game.

Last year, national champ Michigan finished No. 1 with a stop rate of 81.6% in its games against FBS opponents. The top 25 teams in the final 2023 stop rate standings won a total of 249 games, with seven earning conference titles. Great teams find a way to get stops in critical situations.

Stop rate is not an advanced stat and is no substitute for Bill Connelly's SP+ or other more comprehensive metrics. It's merely a different method for evaluating success on defense.

It's not surprising to see the Vols atop this list. They're the only team left in FBS that has held every opponent they've played under 20 points. They've been a top-10 unit nationally in a bunch of important ways: stopping the run, preventing explosive plays and generating negative plays.

But what really stands out when you take a closer look at Tennessee's success on defense is how dominant they've been on critical downs. This is the No. 1 defense in FBS in third-down percentage (24.3%) and fourth-down percentage (21.4%), and they're the best at preventing touchdowns in the red zone, with just eight TDs surrendered in 25 attempts.

The way the Vols have played in sudden-change situations has also been remarkable. Their offense has turned it over 11 times this season. One was a pick-six by NC State. In the 10 other times their defense has taken the field after a turnover, they've allowed a total of zero touchdowns and one field goal. The average FBS team is giving up 2.8 points per drive in those situations. The Vols are giving up 0.3.

Josh Heupel has enjoyed good staff continuity on this side of the ball during his tenure, with defensive coordinator Tim Banks and three of four assistants working together since 2021. They're winning with a lineup of mostly homegrown talent that is veteran up front but starting a bunch of sophomores on the back end who'll keep getting better.

They've had to overcome the loss of middle linebacker Keenan Pili, a team captain, to a season-ending torn ACL, but they keep figuring out a way to get the job done against SEC offenses.

Heupel is winning this year with defense and one of the best rushing attacks in the country. They passed their biggest test yet against Alabama, and now a bigger one looms at Georgia. If the Vols' defense keeps this up and Nico Iamaleava can step up in November, Tennessee could end up being one of those teams nobody wants to run into in the College Football Playoff.

Here are a few more stop rate updates to note following Week 10:

• The best stop rate defense in college football since Oct. 1 has been Notre Dame. The Fighting Irish got stops on 83.3% of drives over their last three games. The next-best Power 4 defense over the past month was Wisconsin at 76.8%, even after giving up 42 against Iowa. The Badgers did drop from 12th to 22nd in this week's stop rate standings.
• Sam Houston has the second-best stop rate in FBS since Oct. 1 at 81.6% over its last four games. The Bearkats are 7-2 and their defense has given up 14 points or less in six of those wins. They've moved all the way up to No. 12 in this week's stop rate standings.
• Indiana continues to be the most improved defense in the country in stop rate. The Hoosiers finished 112th in the country at 54.3% in 2023 but pulled off a total portal rebuild and currently rank 8th with a stop rate of 75.9%.
• Louisiana Tech was the lone team to move to the top 25 this week, climbing to No. 24 after getting 11 stops in a 9-3 loss to Sam Houston.
• Duke (26th) and Nebraska (27th) dropped just outside of the top 25 this week following their losses to Miami and UCLA, respectively.

Note: All data is courtesy of TruMedia. Games against FCS opponents and end-of-half drives in which the opponent took a knee or ran out the clock were filtered out.