GREENSBORO, NC – MARCH 15: Head coach Mike Krzyzewski of the Duke Blue Devils yells to his team against the North Carolina State Wolfpack during the semifinals of the 2014 Men’s ACC Basketball Tournament at Greensboro Coliseum on March 15, 2014 in Greensboro, North Carolina. (Photo by Streeter Lecka/Getty Images)

Despite a five-point halftime deficit, Duke was able to come away with a scrappy, nine-point road win against Georgia Tech on Tuesday to raise its record to a game over .500 in the ACC.

Did I really just type that sentence?

Winning is always better than losing, of course, and props to Duke for winning the second half by 14 points to leave Atlanta with a victory. However, Duke’s games against Georgia Tech are rarely in doubt. The Blue Devils haven’t lost to the Yellow Jackets since 2010, and this year’s Georgia Tech team is nowhere close to an NCAA Tournament contender. But that’s life for Duke in what has become a nightmare of a year.

It wasn’t supposed to be that way. Duke came into the season ranked fifth in the country, with the potential to repeat as national champions. The Blue Devils returned star sophomore Grayson Allen and senior forward Amile Jefferson, and they brought in potential one-and-done sensation Brandon Ingram. That roster isn’t as loaded as last year’s roster, which featured superstar freshmen Jahlil Okafor and Tyus Jones, but that’s still a top 25 roster.

And yet, Duke has fallen out of the top 25 for the first time in eight years after a disastrous start to ACC play. The Blue Devils have played four teams in the top 50, and they’ve lost to all four of them. Two of those losses, against Notre Dame and Syracuse, came at home, where the Blue Devils are nearly unbeatable.

So how does a team with a roster full of McDonald’s All-Americans and one of the greatest coaches of all-time go from NCAA Tournament champion to this? Oftentimes the answer to a question like this is complicated, but for Duke it’s rather simple: defense.

Duke’s offense is the best in the nation, according to KenPom, thanks to the scoring prowess of Allen and Ingram. But the Blue Devils’ defense ranks 130th nationally in KenPom, giving up 1.012 points per possession. That’s on track to be the worst Duke defense of the advanced stats era. The second-worst defense came two years ago, when the Blue Devils ranked 116th in the nation and lost to Mercer in the first round of the NCAA Tournament.

Offense is almost always Duke’s strength, and although the Blue Devils are never bad under Mike Krzyzewski, defense has decided just how good they can be.

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The three mediocre-or-worse Duke defenses were part of the only three teams to rank outside the KenPom top 10. The previous two lost in the first round of the NCAA Tournament, to Mercer and Lehigh, despite having top 10 offenses.

There was some degree of luck to those results — Duke would probably win those games if played again, but historically, the Blue Devils put themselves in bad positions when they don’t play good defense.

The good news for Duke this year? The problems on defense are fixable. The bad news? If they aren’t fixed, the Blue Devils are putting themselves in position to be upset by a hot-shooting mid-major team once again come March.

That’s because this Duke team struggles most at defending the three. Simply put, it’s not that Duke lacks athleticism or size, it’s that the best way for Duke to fix its perimeter defense is getting in the right spot and putting a hand up, something that hasn’t been fixed yet, and it’s a big part of why the Blue Devils are suddenly a middle-of-the-pack ACC team.

Even when teams aren’t able to beat Duke’s big men inside, they’ve found plenty of opportunities beyond the arc, as the shot chart from Shot Analytics shows.


Not only is this a problem for ACC play—Duke has pretty much played itself out of a regular season conference title—it’s also going to be a problem in the NCAA Tournament. To win the National Championship, teams have to be able to play good perimeter defense, because over a stretch of six games, someone is likely to get hot.

Given what we’ve seen from past years, Duke’s biggest concern right now isn’t a national title, it’s avoiding another first round upset. Because no matter how much the Blue Devils score, they’ll have to be able to stop a team that gets hot. Just like in the first-round exits of 2012 and 2014, there’s little evidence they’ll be able to do it.

About Kevin Trahan

Kevin mostly covers college football and college basketball, with an emphasis on NCAA issues and other legal issues in sports. He is also an incoming law student. He's written for SB Nation, USA Today, VICE Sports, The Guardian and The Wall Street Journal, among others. He is a graduate of Northwestern University.