Last month I laid out the one stat on offense that will define the Badgers’ 2020 season. Today, we’re looking at the defensive side of the football and finding the one area that will dictate whether Jim Leonhard’s defense is able to repeat their impressive 2019 campaign.

Badger fans know well that the 2018 season was a disappointing one on the defensive side of the football. A combination of youth in the secondary and injuries to key contributors handcuffed a unit that ended up finishing the season with more than 150 rushing yards-per-game allowed and almost 350 total yards-per-game allowed.

The 2019 unit, then, bested the squad from the year before in nearly every category, finishing the year only allowing 101 rush yards-per-game, a 51.7 completion percentage, 187 pass yards-per-game and 288 total yards-per-game.

What was the biggest difference between the two teams, aside from many of the key contributors returning for the 2019 season?

Two things that in the big picture are directly related to each other.

No. 1: a full 1.1-yard difference in their opponents’ rush yards-per-attempt.

No. 2: a more-than 10 percent difference in the rate at which their opponents converted their third down chances.

Like Wisconsin’s offensive attack, Leonhard’s defense prides itself on being tough against the run and controlling the opponents’ ground game.

In 2018, for various reasons, the defense got ran over and, as a result, saw the entire field open up for opposing teams to use run fakes and get young corners to make mistakes on the outside.

Specifically, that year Leonhard’s defense gave up 4.4 yards-per-attempt on the ground and, as mentioned earlier, 155 rush yards-per-game.

Those tallies are both the highest any Badger defense has allowed since the 2005 squad gave up 4.5 yards-per-rush and 165.8 yards-per-game on the ground. For reference, since 2005 the Badger defense have allowed more than 140 rush yards-per-game one time other than 2018 and more than 130 just three times.

Comparing it now to 2019, the team gave up just 3.3 yards-per-attempt and 99.8 yards-per-game on the ground, both impressive numbers by anybody’s standards and a massive improvement from the previous year.

This improvement played a large role in the 6.5-point difference in opponents scoring-per-game and, therefore, the difference between a 10-4 record (with two losses coming against Ohio State, one of the best teams statistically in the last 15 years) and an 8-5 record.

If that was too many numbers and not enough about what it meant to the unit specifically, the insane rushing numbers the Badgers gave up in 2018 handcuffed the young secondary, kept the opposing offense on the field, allowed opponents to control the game like the Badgers so often do with their rushing attack and, finally, allowed teams to have success in stat No. 2 that will be so important to the 2020 season: third down conversion percentage.

The two stats are correlated because when an opposing team is able to run the ball in early-down situations and set up third-and-short chances, their conversion rate will understandably be a lot higher.

And what has been made clear for years now, specially in the Badgers’ case, winning the time of possession battle and controlling the game with the ball in your offense’s hands is how you win football games.

The first step in this is getting the defense off the field by stopping the opponent on third down.

I mentioned the difference above but, specifically, the 2018 defense gave up a 37.43 percent conversion rate on third down. The 2019 team? 27.27 percent.

This ten percent increase equated to the total of 19 extra conversions by the opponent, or 19 more chances for teams to score and keep Jonathan Taylor and the Badger offense off of the field.

Does stopping the opponent on third down start with stopping the run on first and second down? Absolutely. But a ten percent difference is significant no matter how long the conversions are.

Looking forward to 2020 now, Leonhard will need to try to recreate the production of now-NFL linebackers Chris Orr and Zack Baun and find ways to stop opposing offenses without those two players leading the defense.

Will it be an easy task to find 24 sacks, 33.5 tackles-for-loss and 153 total tackles? No, it won’t. But on the bright side the unit now has future-NFL linebacker Jack Sanborn quarterbacking the defense, a great run-stopping safety tandem in Eric Burrell and Reggie Pearson and an up-and-coming defensive tackle Keeanu Benton who showed flashes of absolute dominance last season as only a true freshman.

The phrase “ball control” sounds at times like a secret Big Ten saying that really just means play old-school football and shame the Big 12 and PAC 12 for not playing a lick of defense.

It really matters though and, as pointed out above, was one of the biggest differences between a struggling 2018 defense and an absolutely dominant 2019 one (again taking into account that their worst performances came against Ohio State, one of the best offenses statistically in college football history).

Only time will tell but if the 2020 squad is able to recreate the production from last season and give quarterback Jack Coan more chances to put points on the board, we could be in for a special season in Madison,