The Philosophy Shift Powering Illinois Basketball's Remarkable Rise

For quite some time in the Brad Underwood era at Illinois, his teams had prided themselves on running opponents off the three-point line, protecting the rim and forcing tough twos. That was the Illini defensive philosophy. And, as far as the analytics were concerned, that certainly seemed to be the recipe for success.

But that wasn’t working for the Illini – who, over the past two seasons, finished No. 40 (2024-25) and No. 80 (2023-24) in defensive efficiency, per KenPom. And heading into the 2025-26 campaign, with newly appointed defensive coordinator Camryn Crocker putting his fingerprints on the product, Illinois was ready to make a few changes.

Ever since Dr. James Naismith invented the game, the highest percentage shot in basketball has always been the layup. Sort of goes without saying. The logic: The closer the shooter is to the hoop, the easier it is to make a shot.

The Illinois defensive adjustment that has fueled its recent surge

Feb 1, 2026; Lincoln, Nebraska, USA; Illinois Fighting Illini head coach Brad Underwood walks onto the court before the game against the Nebraska Cornhuskers at Pinnacle Bank Arena. Mandatory Credit: Dylan Widger-Imagn Images | Dylan Widger-Imagn Images

With that in mind, the Illini have put a heavy emphasis on keeping opponents out of the paint and clogging it when they arrive. If they are forced to give up a few more looks from deep, so be it.

“It’s just math,” Underwood said of Illinois’ decision to channel its defensive efforts on protecting the interior, instead of running opponents off the line. “Layups and close-in shots are a much higher percentage. And then [we] utilize our size and length to just contest. … It’s just been math. We’re going to give up a few more and teams are going to make a few more, but I think it’s been phenomenal for us to just not give up layups.”

Z with ANOTHER block

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— Illinois Men's Basketball (@IlliniMBB) February 5, 2026

Especially given Illinois’ size and length across the roster, there are few teams as capable of guarding the basket and still getting solid contests on three-point shooters more often than not.

Yet it’s impossible to protect the rim at an extremely high level without leaving three-point shooters unattended on occasion. And in this basketball era – which is predicated on offenses getting up threes at a high rate – it wasn't easy budging Underwood (who has built his own offenses around three-point shooting) off a defensive philosophy that preaches shutting down perimeter shooters as priority No. 1.

“I was the hardest one to convince,” Underwood said. “We held teams without a three at different times. And to give that up was challenging for me. It was challenging early in the year. But I’m all in.”

The tipping point? Illinois’ last loss: at home to Nebraska. Although the Cornhuskers’ Pryce Sandfort stole the show with his six made triples (NU made 12 as a team), it was actually the visitors’ two-point efficiency that flipped the game on its head, as they shot 20-for-36 from inside the arc.

“Probably the most challenging after the Nebraska game here [in Champaign] – when they torched us,” Underwood said. “They shot 60-some percent from two. But that’s when I knew we had to commit to it and I had to buy into it and I had to stop barking every time somebody gave up a three – and they made it. And just understand that for the long term, this is what we’ve got to be good at.”

Underwood and the Illini have indeed committed – and they have reaped the rewards. In the second matchup with Nebraska, Illinois managed to survive a blistering-hot long-distance performance from the Cornhuskers (15 made threes) behind stingy two-point defense (NU shot just 41.7 percent on twos).

Illinois' offense has been humming all season long, but it’s that defensive adjustment that has truly elevated the program into the national title discussion and fueled the Illini's 12-game win streak.

With No. 10 Michigan State up next, the Illini will need to carry that defensive momentum into East Lansing on Saturday. Facing a typical Tom Izzo squad – defensive-minded and dominant on the glass – all of Illinois’ own strengths will be tested, and a marquee defensive performance may be necessary for the win streak to survive.