Offense had stood out all season for Illinois, only for the defense to step up in March Madness.

Arizona and Michigan have been part of college basketball's top tier all year with elite play at both ends of the court, and they've been even sharper at the offensive end in the NCAA Tournament.

Now that trio joins UConn for this week's Final Four in Indianapolis. The Huskies and Illini meet in Saturday’s first semifinal, followed by the Wolverines and Wildcats.

All four teams rank in the overall top 10 of data-driven college basketball rankings for KenPom, Evan Miyakawa and Bart Torvik going into the Final Four. That includes the Wolverines and Wildcats ranking 1-2 for all three currently, as well as posting some of KenPom's best net-efficiency rankings ever recorded.

Illini's defense

Illinois (28-8) entered the NCAA tourney ranked second in KenPom's adjusted offensive efficiency by averaging 131.2 points per 100 possessions while ranking just 28th in defense (99.1). Yet the South Region champion's defense has allowed .976 points per possession in the NCAA Tournament to lead the remaining four teams.

“We’ve been very good throughout the season at times,” coach Brad Underwood said before the regional final win against Iowa. “We just haven’t been that consistent.”

Illinois allowed Penn, VCU, Houston and Iowa to score on just 41.2% of their possessions. The Illini also dominated the glass (plus-16.3 per game) to grab the rebounds that completed those defensive stops.

They've done it all with the nation's tallest roster, with seven players from Saturday's eight-man rotation standing 6-foot-6 or taller. That has included an influx of European talent, including Croatian twins Tomislav (7-1) and Zvonimir Ivisic (7-2), as well as 6-9 forward David Mirkovic from Montenegro. The outlier among that big lineup, 6-2 senior guard Kylan Boswell, is a strong backcourt defender.

UConn (33-5), meanwhile, has scored on 52.2% of its possessions going back to the second-round win against UCLA, with a high of 54% in Sunday's comeback from 19 down to shock top overall tournament seed Duke.

Terrence Oglesby, an analyst with ESPN and Field of 68, pointed to the Illini's ability to play in the gaps to disrupt offenses trying to move the ball and space the floor to create mismatches or lanes.

“Positionally, they're just elite on top of being massive,” said Oglesby, a former Clemson player. “You go to the Balkans to grab all these guys, and they're huge and they've also been well coached coming all the way up. ... The good part about being pretty gap-heavy is the fact that if you're huge, you can still get out to shooters."

Offensive flow

Michigan (35-3) has the most efficient offense of the Final Four teams, averaging 1.361 points per possession in tournament wins over Howard, Saint Louis, Alabama and Tennessee to edge Arizona's similar average (1.341).

The Midwest Region champion became the first team to score 90 points in every game through to the Elite Eight since UConn did it in 1995 before falling 102-96 to eventual champion UCLA. Dusty May's Wolverines are shooting 55.9% through four games, including 44.6% (45 of 101) from 3-point range, and have scored on 60.4% of their tournament possessions.

Before the Sweet 16 win against Alabama, guard Roddy Gayle Jr. said May's system allows the Wolverines to play “super free.”

“He does a lot of free-flow offense,” star Yaxel Lendeborg said. “He has certain sets, but the sets aren’t necessarily for shots. It’s just for movement, just to get the defense out of their shell, and then attack off those mistakes."

Net efficiency

The Wolverines' semifinal against fellow 1-seed Arizona (36-2) will pair teams with all-time great KenPom efficiency metrics.

KenPom bases efficiency on points scored or allowed over a standardized 100-possession pace to eliminate tempo as a factor. Overall rankings are determined by net efficiency in terms of how much a team’s offensive data outpaces its defensive numbers.

Michigan currently leads the country at plus-39.02 after the regionals, followed by Arizona at plus-38.76. By comparison, only two teams have finished a season with higher KenPom numbers going back to the 1996-97 season: Duke in 1998-99 (plus-43.01) and Duke last year (plus-39.29).

“These are these massive teams that also have enough shooting. but they’ve leaned into the everything else," Oglesby said. "They've leaned into the controllable aspects: rebounding, being big, being physical. ... I wouldn’t say that the championship game is Michigan and Arizona, but those two teams have just been a freight train going through.”

Neither of those high-efficiency Duke teams managed to cut down the nets. The first lost to UConn in the title game and the second fell a year ago to Houston in a late collapse in the national semifinals.

What's ahead

The season's final three games will pair strength-on-strength in the halfcourt.

The four teams have played man defense on 97.3% of their combined halfcourt possessions, according to Synergy. Arizona, Michigan and UConn all rated as “excellent” in the 91st percentile or better, while Illinois is rated “very good” in the 81st percentile.

Yet Synergy rates all of those teams as “excellent” in running halfcourt offense against man defense, with Illinois (97th percentile) and Michigan (96th) as the best.

The key for Saturday could be which teams can get out in transition to avoid tussling with set halfcourt defenses. That could favor Illinois (97th percentile) and Arizona (94th) as the top teams in transition offense with “excellent” ratings from Synergy.

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AP March Madness bracket: https://apnews.com/hub/ncaa-mens-bracket and coverage: https://apnews.com/hub/march-madness

Michigan had just dispatched Alabama to advance in the NCAA Tournament when coach Dusty May was asked about his top-seeded Wolverines becoming the latest Big Ten team to eliminate a Southeastern Conference opponent.

“You know, college basketball has been cyclical forever,” May said after Michigan's 90-77 win in the Midwest Region semifinals. “Hopefully this is a long cycle for us in the conference.”

For this year, at least, the Big Ten has snatched the March Madness spotlight that was locked on the SEC last year.

The Big Ten had a league-record six teams reach the Sweet 16 and now has tied the tournament record with four teams in the Elite Eight, increasing its chances of breaking through for the league's first title in more than a quarter-century. That includes an all-Big Ten matchup in Saturday's South Region title game that will send either No. 3 seed Illinois or No. 9 seed Iowa — which upset reigning national champion Florida in the second round — out of Houston and on to Indianapolis for the Final Four.

No other league has more than one team in this weekend's regional finals.

“The talent in our league is very good,” Purdue coach Matt Painter said Friday, ahead of his team's West Region final against top-seeded Arizona. “I think you’re seeing that here in the tournament. Like very good. I think it’s been about as good as it’s been for a long, long time.”

The results are backing that up.

Big Ten schools were highly ranked entering March Madness

Only three leagues had put four teams in the regional finals since the tournament expanded to 64 teams in 1985: the Big East in 2009, the Atlantic Coast Conference in 2016 and the SEC last year.

Now the Big Ten has done it, too, after getting three teams to the Elite Eight four other times, most recently in 2014. And the league nearly got five teams there, with Michigan State losing a tight contest with UConn on Friday night.

Last year, all the talk was about the SEC's records of 14 tournament bids and seven Sweet 16 teams. This year, the Big Ten is the standout, with four of its teams having taken out SEC opponents so far — including Purdue beating Texas on Thursday and Michigan's win against Alabama.

It could add a fifth, too, with the Wolverines set to play Tennessee in the Midwest Region final on Sunday.

It shouldn't be a surprise, considering the Big Ten had a national-best six teams ranked in the AP Top 25 entering the NCAA Tournament, while its nine bids were behind only the SEC's 10.

First-year Iowa coach Ben McCollum, who has the program in its first regional final since 1987, admitted he was “curious” as to how difficult his first run through the league would be. His team went just 11-11 between Big Ten regular-season and tournament play, yet here it is, playing for a Final Four spot.

“The good part is it helped a lot of us in the tournament,” McCollum said Friday of the league's difficulty. “I think sometimes it can hurt you too, just because you get beat up a little bit, maybe lose your confidence. It helped us from a process perspective and we continued to grow and get better, and be better and better as long as we focused on that.”

Big Ten has money but a long title drought

The Big Ten's run marks the second straight year that the two most cash-flush conferences have dominated the tournament. The Big Ten generated the most revenue ($928.1 million) and distributed the most to its member schools ($63.1 million average) for the 2023-24 season, according to tax documents.

That figure outpaced the SEC's $839.7 million in total revenue and $52.6 million in average payout to full members for that same season, which is the most recent year in which all power conferences have filed tax documents. And that only helps when it comes to managing the always escalating costs for staff, facilities and roster building.

“I know our league is incredibly tough,” May said Friday night. “The coaches are off the charts, but I want to give the administrations a lot of credit. There’s a bunch of well-run athletic departments in the Big Ten.”

The only trick now is for the league to get a team to the final Monday night of the season and actually cut down the nets. The Big Ten hasn't had a school win the tournament since Michigan State gave Izzo his lone title in 2000.

“I think the Big Ten Conference is the best conference in the world,” Wolverines senior guard Roddy Gayle Jr. said Thursday. “Obviously we want everybody in the Big Ten to be successful. But just kind of seeing the success that the conference has had in the tournament is really good. And I think it speaks to how good we were in the season to be able to finish first.”

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AP March Madness bracket: https://apnews.com/hub/ncaa-mens-bracket and coverage: https://apnews.com/hub/march-madness