Is Duke a Title Contender? Not with This Defense

Duke takes the stage Thursday for its first of two rivalry games against North Carolina, and head coach Mike Krzyzewski arguably has one of the most talented rosters he's ever taken to Chapel Hill.

The Blue Devils, in terms of NBA potential, have the best starting five in college basketball. All five starters could end up as first-round picks. Yet somehow this is a question worth asking: Is Duke a national title contender?

The Blue Devils are not a good defensive team, and history shows us that bad defensive teams do not win national titles. In the KenPom era (dating back to 2002), no champion has finished outside the top 20 in adjusted defensive efficiency.

Duke ranks 72nd.

The caveat, and one heard often this year, is that a team can improve defensively. Duke's 2014-15 national title team is referenced as the reason it could suddenly click for Coach K's defense. That group entered the NCAA tournament ranked 63rd in adjusted defensive efficiency and somehow became elite on that end, jumping up all the way to 11th.

It's probably time to trash that example. It was an outlier and was spearheaded by a great defensive talent in Justise Winslow. This Duke roster doesn't have a Winslow, and the players who make up the core aren't good defenders individually and definitely not collectively.

The numbers are troubling, and so is the tape. 

What the Numbers Show

Through the years, you could bank on Duke running teams off the three-point line and usually keeping three-point percentages low. In the KenPom era, the Blue Devils have ranked in the top 20 in three-point prevention in every season but one (2012-13), and that team ranked 24th. Before this year, no Duke team had ever allowed opponents to attempt more than 30 percent of their shots from deep.

This season, Duke opponents are shooting 35.8 percent of their attempts from three-point range, ranking 111th in defensive three-point rate. That's still below the national average (37.4), and teams are taking more threes than ever across the country. Yet not only is Duke not preventing attempts like usual, but those shots are falling at the highest clip (34.5 percent) Duke has allowed since 2000.

That three-point accuracy is still below the national average, but it's telling that this team is the worst at something out of the last 18 teams Krzyzewski has coached. When the Devils do try to run a shooter off the three-point line, their closeouts are not effective. That leads to forced rotations, and this team is not good when forced to play help defense.

The other two troubling numbers for the Blue Devils are defensive rebounding percentage (ranks 194th) and turnover rate (ranks 281st).

Krzyzewski's teams have been less aggressive in recent years at trying to force turnovers, but none of his teams in the KenPom era have been worse at it than this group.

The fact that his team isn't great on the defensive glass is not unusual looking back on his past, but it is concerning when taking into consideration he has the best offensive rebounding team in the country. It's one with two forces up front (Marvin Bagley and Wendell Carter), and they only dominate the glass on one end. 

A Personnel Problem

Some of Duke's problems come down to youth and personnel. This is Krzyzewski's youngest team ever, and since he began actively recruiting one-and-done players, only the title team ended up as a solid defensive team.

It's hard to get freshmen to buy in defensively and understand college concepts. Every one of Duke's 5-star freshmen—and there are four in the starting lineup—has been the go-to guy on his teams throughout his life. They've likely never been seriously challenged to defend. Players of their ilk are usually told to "just go get buckets, young fella!"

As pure athletes, you would think Duke would be better.

Bagley is a quick-twitch player who would seem to fit as a switchable defender. Carter has a 7'3" wingspan and moves well for a center offensively. Grayson Allen and Gary Trent are both decent athletes with size, and Trevon Duval has a 7'0" (!) wingspan and is lightning-quick.

But if you study each player individually, only Duval would be considered a plus defender. Allen and Trent are not good on-ball defenders and struggle keeping ball-handlers in front of them; Carter is a little heavy-footed and slow to react; and Bagley is also not great defending on the ball on the perimeter and isn't instinctive as a defender.

Some of this could be overcome by playing together and with effort, but, well, let's throw it to Coach K for his now-viral reaction to the loss against St. John's, a winless team in the Big East:

"They played with an enthusiasm and a togetherness that I'm sure they liked, and it was tough for us to defend them. I thought they made us look bad, but then we made ourselves look bad. We did not play basketball the first 32 minutes worthy of our program. We had blank faces. We didn't talk. We were like five individuals out there, and it was disgusting, really."

What opposing teams have figured out is that if you spread the floor against the Blue Devils and run good offense, eventually they're likely to break down. There's a stat that shows this too: Duke ranks 306th in the average length of a defensive possession (18.0 seconds). This is the only Duke team to rank outside the top 200 in the nine years of data Ken Pomeroy has tracked possession length. 

Visual Evidence

I went back and closely studied two teams that had unexpected success against Duke (North Carolina State and St. John's), and a few themes popped out.

1. Duke Cannot Guard Ball Screens

This was an issue back in 2014-15 with Jahlil Okafor, and Carter has some similar limitations.

He's uncomfortable defending away from the bucket, so he often ends up in no-man's land trying to sag off to take away a drive but turns into a non-factor. In Carter's defense, pretty much every guy on the floor is part of the problem when teams are running ball screens against the Devils.

The defender on the ball is not doing an effective job of fighting through the screen, and then because the screener's man is typically trying to hedge or cut off a driving lane, his man is rolling and Duke's help-side defenders are slow to react—if they react at all.

It happens again and again and again.

2. The Effort Stinks

This isn't always the case. There are possessions where Duke is going hard. As young teams tend to be, this is a spurty group. They obviously play better when they play with energy, and they've played with great energy when they've gotten behind, which is why they have a lot of comeback wins.

But too often the effort isn't there. Two plays from the loss at NC State are telling.

In this play below, NC State's Omer Yurtseven grabs a rebound with seven minutes, 40 seconds left on the clock. Six seconds later, the Devils are so leisurely working their way back on defense that three players are not even part of the play when Sam Hunt drills a wide-open three.

This play was followed by an immediate Coach K timeout.

The second play is a repeat of the first. NC State grabs the rebound at the 9:49 mark. Five seconds later, Duval, the fastest player on the court, has yet to cross the three-point line.

Bagley, who might be the second-fastest, is also loafing back. By simply hustling, he likely could have forced NC State to run its half-court offense. Instead, Abdul-Malik Abu throws down an uncontested dunk.

It's worth noting that Coach K has not shown a lot of trust in his bench, and his starters are playing a lot of minutes, so they could be tired. But the lack of effort defensively shows up too often to make that excuse.

3. Zone Is Not the Answer

One other reason that Duke's average defensive possession could be longer is that Krzyzewski is playing more zone than ever before.

It makes sense to go that route when he goes to bigger lineups that include three of Bagley, Carter, Javin DeLaurier or Marques Bolden, but do not be fooled into thinking this is a tactical move. It's not. He's often going zone because his team cannot guard in man-to-man.

Well, the zone stinks too.

Great zones are active, and Duke's is not. Duke plays zone defense like a youth team with a coach who doesn't want to teach defense and just throws his kids in a zone with the instructions to "guard an area."

The problems are similar to what ails Duke in man-to-man. The Devils do not communicate well, so when one man should be moving, he's often a tick behind. The intensity and focus isn't there, and it's not hard to generate an open look against Duke's zone.

Notice in the video examples that it's not fantastic ball movement that sets up easy shots. It's players late to react, often the result of poor communication. 

Is There an Answer?

There are some things the Devils can do better with the personnel they have; most come down to effort and attention to detail. This group is so talented offensively that addressing those issues would go a long way.

This is not ever going to be a great defensive team unless Bagley can morph into the 2015 March version of Winslow and Coach K gets the rest of his guys to communicate and play team defense. That's probably not going to happen with Bagley this season.

Maybe he becomes better in the NBA defensively, but it's not likely he reaches Winslowian levels this year. Coach K is a Hall of Famer for a reason, but most teams usually are what they are at this point in the year, as Pomeroy wrote recently.

The biggest concern for the Blue Devils could be the schedule. They've put up these crummy defensive stats with a weak conference slate to date.

Through 10 conference games, Duke has played four top 50 KenPom teams and only two in the current Associated Press Top 25 (Miami and Virginia). Out of the remaining games left, Duke plays seven against top 50 opponents, starting Thursday against North Carolina.

We should have a better idea by the end of the regular season whether the Devils can put up worthy defensive efforts over consecutive games against quality opponents. If their better defensive numbers over these final eight games are closer to that of a top 20 defense, then it's much easier to justify them as a national title pick.

But if this is the defense the Devils take into March, it's hard to see this team, even with all its talent, winning the national title.

C.J. Moore covers college basketball at the national level for Bleacher Report. You can find him on Twitter, @CJMooreHoops.