When he left North Carolina for Kansas, there was only a handful of ways Roy Williams diverged from his mentor. One of them was on defense, where he committed to attacking the ball before it crossed midcourt and pressuring passing lanes.
Flash forward 15 years, with Williams long established in Chapel Hill and coaching a team that, unusually for him, lacks any kind of inside defensive presence. The only answer he could come up with was to go back to what Dean Smith and Bill Guthridge did that he didn't like: Being more passive and protective on the perimeter.
“Only time in my life I've ever done that,” Williams said Thursday. “We call it '21' defense. The last two or three years coach Smith coached he went to 21 defense. Coach Guthridge went to 21 defense. I never did. I came back here and coach said he wished he had never done it. Told me to stick to my stubbornness, is what he called it. We've changed, and we still haven't gotten what we wanted to get.”
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On the other side of the rivalry, Mike Krzyzewski built Duke's dynasty on aggressive man-to-man defense, which was a trademark of the program right up until the one-and-done era. This year, with yet another young team starting four freshmen, there hasn't been time to teach those principles.
After all these years, Duke has become a zone team, and not just because Krzyzewski spent too much time with Jim Boeheim at the Olympics.
“It is a zone team,” Krzyzewski said Friday. “I hope we're better than Syracuse. I hope we're the best. Whatever we're playing, I hope we're the best. We don't want to be second best.”
There isn't an ACC regular-season title on the line for the first time in three years Saturday when Duke hosts North Carolina in the back end of the annual rivalry. What there is instead is two teams still searching for their defensive identity at this late point in the season, still trying to embrace it before it's too late, heading into the postseason gambling that they can still get it right.
For North Carolina, the problem is one of personnel more than youth, although youth is part of it. The Tar Heels were counting on one of their two talented freshmen big men – Garrison Brooks and Sterling Manley – to emerge as a force in the post by this point. Despite flashes, neither has. For a program that has consistently had a rim-defending post player under Williams, that has necessitated some defensive remodeling.
With Luke Maye and Cam Johnson the nominal post players in the starting lineup, the Tar Heels unlock offensive potential at the expense of inside defense. Earlier in the season, that led to players overhelping on the perimeter without the safety net behind them and too many opposing 3-pointers. The combination of getting beat outside and not having a presence on the inside left North Carolina giving up too many easy baskets.
The only way to fix it – absent a breakthrough by Manley or Brooks, which could yet happen – was to do the same thing Williams criticized Smith and Guthridge for doing: Back off.
“Now I'm picking up behind halfcourt,” North Carolina's Joel Berry said. “You know, I'm an aggressive guy. I like to get after the other point guard. It's just a little different having to be so conservative. Instead of being out there denying and having to help and then get out and close out, it makes it easier because you're already in the lane and all you have to do is close out. While it sounds so simple sitting here, it's totally different out there on the court.”
It didn't look very good in Tuesday's loss to Miami, but it was merely one of many things – bizarre mental breakdowns leading to embarrassing turnovers, most notably – that went wrong for the Tar Heels.
As for the Blue Devils, they have been trending away from man and toward zone since the Mercer loss in 2014, but this season has become the farthest extension of it. Some of that is because of the issues teaching the principles of man defense to players who will be moving on after the season – to a certain extent, it's a waste of valuable coaching time to get halfway through lessons that won't ever be finished – and some of it is because of Duke's specific mix of players this season
In Monday's loss to Virginia Tech – defense wasn't the issue, holding the Hokies to a commendable 0.97 points per possession, continuing a strong run for the Blue Devils – Duke started a lineup that was all 6-foot-5 or taller, creating a 2-3 zone like a prison fence, the kind of lineup that Boeheim mumbles about in his sleep during his best dreams. But even a front line of Marvin Bagley III, Wendell Carter Jr. and Gary Trent Jr. goes 6-11, 6-10 and 6-6.
"I don't think I've ever seen a Duke team play this much zone," Duke's Grayson Allen said. "And for me, that's not a knock on us. It's just Coach sees that with how big our team is, how athletic our team is, our best defense can be that zone and we can play it really well. He's open to adjustments."
These are strange times for programs built on founding principles that at times have seemed irrevocable: Duke's defense and North Carolina's post presence. The former had to change because of the personnel; the latter's personnel forced a change in defense.
Both teams will head into the postseason with high expectations regardless of what happens Saturday. They'll also head into the postseason in the unusual position of being something different than they usually are, still trying to figure it out.
Sports columnist Luke DeCock: 919-829-8947, email@example.com, @LukeDeCock