Illinois’ defensive improvements in 2019-20 were considerable. Abandoning the high pressure, force-a-turnover-at-all-costs system paid dividends. It was OK to force tough shots or funnel opposing offenses into all 7 feet and 290 pounds of Kofi Cockburn.

The Illini finished last season ranked 35th nationally in adjusted defensive efficiency at 93.7. That’s points allowed per 100 possessions adjusted for quality of opposing offenses, the site of each game and when each game was played (recent games weighted more heavily). It was the best defensive efficiency of any Brad Underwood team — Oklahoma State and Stephen F. Austin included — and the best at Illinois since the 2013-14 team posted a 93.4 ADE and ranked 14th in the country.

That improvement, though, apparently wasn’t enough for Underwood. The Illini coach said as much in a recent podcast with Andy Katz. If Illinois wants to be elite, it has to trend closer to the top 15 in ADE. Underwood made a point that teams not in the top 15 don’t make the Final Four.

So let’s take a look at that. Underwood’s point, for the most part, bears out. Ken Pomeroy has tracked ADE since 2001-02. In the previous 18 seasons a Final Four was played, exactly two-thirds of the teams to reach the Final Four had a top 15 defense. That includes an Illinois team in 2004-05 that ranked fourth nationally in ADE (and third in adjusted offensive efficiency for good measure).

Still, a third of the teams to reach the Final Four since the 2001-02 season weren’t quite as good defensively. Some just fell outside the top 15. Others were serious outliers. A look at the some of the latter:

➜ The 2002-03 Marquette team was the least efficient defensively to make a Final Four in the last 18 seasons, playing with a 99.2 ADE to rank 109th. The Golden Eagles, of course, had Dwyane Wade, Travis Diener (and now Illini women’s basketball assistant Scott Merritt). Wade, you’d imagine correctly, was fairly instrumental in Marquette’s No. 2 offense.

➜ That same season saw Texas make the Final Four despite ranking 58th (second highest of the 72 Final Four teams since 2001-02). The Longhorns, like Marquette, were hyper efficient offensively.

➜ Butler had the No. 7 most efficient defense when it made the Final Four in 2009-10. A year later without Gordon Hayward? The Bulldogs slipped to No. 46 … and still made the Final Four. They ranked similarly in offensive efficiency, making their Cinderella run as an eight-seed (they won their first four games by 13 points combined) even more unlikely.

Scott Richey

Scott Richey is a reporter covering college basketball at The News-Gazette. His email is srichey@news-gazette.com, and you can follow him on Twitter (@srrichey).