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Joe Boozell | NCAA.com | December 21, 2017

Duke’s defense is struggling, but how much does it matter?

  Duke is 11-1, but it has the No. 74 defense in the country.

Duke is the No. 4 team in the AP Top 25 and sits at 12-1. Grayson Allen looks to have regained his sophomore form, Marvin Bagley is every bit the stud he was touted to be, and Trevon Duval, Gary Trent and Wendell Carter have all shown why they drew so much hype coming into college.

That’s one way to look at Duke’s season thus far. Another: the Blue Devils haven’t played good defense all year. They lost to one team they shouldn’t have (Boston College) and have allowed other teams to stay in games longer than they had any business doing so (Portland State, Indiana, Texas).

Having the best offense in America can cover up a lot of flaws, as we’ve seen. Duke leads the country in offensive efficiency; Allen and Bagley are both legitimate No. 1 options, and Carter, Trent and Duval seem overqualified in their complementary roles. But it’s working on that end. The Blue Devils are rebounding 43 percent of their own misses, which leads the nation, and they make almost 60 percent of their 2s. That’ll fly.

The defensive end has been another story. The Blue Devils rank 74th there, and have allowed some unlikely opponents to go bonkers – Michigan State hanging 81 on them was understandable, but Portland State, Florida, Indiana, South Dakota and Boston College have all gone for 80-plus on the Dukies. The Gators are the only team in that group that sports a top-55 offense. What’s going to happen against the North Carolinas, Miamis and Notre Dames of the world when ACC play rolls around?

We can panic some, but it would be unwise to freak out just yet. Reason one: Duke is extremely young, and young teams typically aren’t good on defense. Allen is the only non-freshman starter, and Javin DeLaurier and Marques Bolden are the only non-freshmen in the rotation; neither averages more than 15 minutes per game. These guys probably got by on defense in high school because they were bigger, stronger and more athletic than their opponents. They didn’t have to worry about nailing pick-and-roll coverages, helping the helper, or deciding when to switch or to hedge and recover. This stuff is likely foreign to them, and it takes time to learn when playing a high level of competition. They'll improve in the next few months.

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Reason two: We’ve seen Duke teams do this before, only to figure it out by March. 2014-15 is the classic example; the Blue Devils were outside of the top 30 in defensive rating most of that year, and allowed a combined 177 points in back-to-back losses to N.C. State and Miami. But Jahlil Okafor, Justise Winslow, Tyus Jones and company locked teams down in February and March, and finished with the No. 11 defense. The defensive issues aren’t size and athleticism-related; they hinge almost entirely on effort, scheme and general awareness. That stuff can be learned.

Then there’s the flip side: 2016-17. Again, a Duke team with lofty expectations started slow on defense… and while it made strides, it never improved enough to perform at a championship level. The Blue Devils finished with the No. 47 defense last year and allowed 88 points to South Carolina in their second round tournament loss.

Duke’s lack of a true point guard was a common talking point last season, but its No. 6 offense was (at least statistically) good enough to win a title. Its defense wasn’t.

Here is where the last 16 national champions finished the season in defensive rating:

Year Team Defensive Ranking
2013 Louisville 1
2008 Kansas 1
2016 Villanova 5
2010 Duke 5
2004 Connecticut 5
2006 Florida 7
2005 North Carolina 7
2002 Maryland 7
2012 Kentucky 8
2017 North Carolina 11
2014 Connecticut 10
2015 Duke 12
2003 Syracuse 14
2011 Connecticut 15
2007 Florida 15
2009 North Carolina 21

So in order to win the title, Duke is either going to have to improve drastically, or do something no team has done since 2002. To fix it, we must identify the problem: we know the Blue Devils have struggled on defense, but why?

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It starts with ball-screen defense. Boston College absolutely eviscerated Duke in the pick-and-roll in its upset win.

Credit the Eagles’ persistence. They put Duke big men in ball screens on nearly every possession and milked what was working; Ky Bowman finished with 30 points, and he was usually the ball-handler in screen-rolls.

It’s unclear what Duke’s pick-and-roll strategy is, which is a problem. There are three options: hedge and recover; switch; or the big man backs off and tries to coax the guard into a mid-range jumper – the last strategy requires an outstanding on-ball defender to fight through the screen in a timely manner. Fifteen-footers are better than 3s or layups, but not if they're uncontested.

The Blue Devils are doing parts of all three, but aren’t fully committing to one – variety is usually good, but not as it pertains to pick-and-roll defense.  

Here’s an example. Duval barely moves to get through this screen, and it allows BC an open jumper. If the strategy was to switch, that’d be fine. But Bagley didn’t show eagerly enough if that was the case. If the strategy was to hedge, Duval didn’t give Bagley a fighting chance:

On this play, Duke executes the first switch nicely but slips up on the second. If Bolden is going to hedge or trap, Bagley needs to make his man use the screen. But he gets caught out of position, and Bowman jab steps the other way and takes him to the rack:

The same idea applies to dribble hand-offs. Again, it’s murky what the strategy is here – Allen switches and takes Trent’s man, but Trent continues to chase his guy, leaving Allen’s wide open for a 3:

Another culprit: overhelping. Duke defenders commonly help one of their teammates who doesn’t need it. Here, Allen does a good job of staying with his man on a drive. But Carter needlessly abandons his assignment to help Allen, forcing Duval to step onto Carter’s guy, which leaves Duval’s wide open for a corner 3.

One more example: Duval doesn’t do a good job of fighting through this screen, but Carter does nice work in containing the ball-handler, who has no clear advantage. Alex O’Connell leaves his man to help anyway, and Duke allows an uncontested 3:

It’s as if the Blue Devils know they should be helping, but aren’t grasping the proper times to act, so it turns into a guessing game. They are identifying threats that aren't there.

None of that looks promising, but there’s good news: this is all fixable. The first step is to simplify things. Duke doesn’t need to reinvent the wheel defensively – it has the athletes to play basic coverages and be fine. It’s unclear whether this is on the coaches or the players – but here’s an idea to help matters:

It starts with giving the best defender on the team, DeLaurier, more of Carter’s minutes – right now, DeLaurier is spending most of his time out of position at the three, but he’d be better suited as a switchable four or five. Carter is a really nice player, but his offensive skillset overlaps with Bagley’s.

Step two: switch more. It would eliminate the miscommunication that is happening so frequently, and while it would force some bigs to check guards and some guards to check bigs, maybe that’s OK? Bagley and DeLaurier are quick enough to handle most smaller players, and forcing an opponent to play mismatch basketball is better than allowing open 3s and layups as a result of botched rotations. Another remedy: playing more zone; that didn’t work against Boston College, but it’s worked against some other teams – most notably Michigan State.

Duke has the tools to figure this out. Perhaps it will; these freshmen should be learning more about college defense as each game passed by.

But keep an eye on this as ACC play kicks off – the Blue Devils have about three months to craft a top-20 defense. The offense could be historically good, but there are two ends to the floor.