In January of 2015, Duke’s defense was in tatters. 

The Blue Devils had just gotten blown out of the water by unranked N.C. State and Miami, giving up a combined 177 points and allowing them to shoot 55.6 percent from deep. Mediocrity, not March wins, seemed in the cards. 

But less than three months later, they rode stifling defense to their fifth national championship. 

Senior guard Grayson Allen sees a parallel between that team he played on as a freshman and 2017’s young but talented Duke team that has been elite on offense, but nothing close to it on the other end of the floor. The Blue Devils gave up 89 points in their last outing Dec. 9 to a Boston College team that had won two conference games in as many years. 

“I do [see similarities] with our curve or progression in how we can get better because of our youth,” Allen said. “If we can figure out the defensive part of it, that’s when we’ll become dominant.”

But that growth is going to have to come quickly. No. 4 Duke will welcome Evansville, the nation’s top 3-point shooting team, to Cameron Indoor Stadium Wednesday at 7 p.m. Despite losing top scorer Ryan Taylor six games in, the Purple Aces have run—or jogged—at one of the slowest paces in college basketball to success from beyond the arc, a test for a Blue Devil defense that will have to make sure every possession counts. 

“They move the ball around really well. They cut really well without the ball,” Allen said. “Off the ball, they constantly screen, get split actions. It’s going to be a game where you have to be awake off the ball. It’s going to be a game where it’s important for our defense to stop them because there probably won’t be as many possessions as we’re used to.”

Evansville (10-2) brings a deep backcourt spearheaded by the duo of Dru Smith and Blake Simmons, who lead its healthy players in scoring and have combined to shoot 55.1 percent from deep. 

Heading into Wednesday, Allen said Duke (11-1) has improved during its break for final exams on its team defense, which has certainly been lacking for major stretches of the season. The Blue Devils have left many shooters open and rank No. 270 in the nation in percentage of points allowed beyond the arc. 

Despite playing strong individual defense at times, Allen thinks Duke is missing one big thing on defense: swagger. 

“We’re developing it,” Allen said. “I like that confident swagger that our team can have, but you have to be able to stop guys to do that. We have to get it done on the defensive end. Once we get a little confident and cocky about our defense, that’s when our whole team attitude will turn that way.”

Head coach Mike Krzyzewski sees the untapped potential also, though more so in terms of athleticism and lack of practice time for a young team than any sort of attitude. 

“We’re not a good defensive team,” Krzyzewski said after Boston College shocked Duke. “But we haven’t practiced either. All we’ve done is play 12 games. We’re young. We’re talented. We’re not as deep. We’re big. That’s a different dynamic on how you have to play defense. We’ve got to get better.”

Despite their prowess from beyond the arc, the Purple Aces will be noticeable smaller than the towering Blue Devils—they have just one rotation player taller than 6-foot-8, forward Dainius Chatkevicius at 6-foot-9. With 6-foot-11 Marvin Bagley III and 6-foot-10 Wendell Carter Jr., Duke's interior defense hasn’t been lacking, but Carter’s foul trouble has kept him off the court at times. 

With the heart of ACC play looming, Allen hopes that he can impart some of the wisdom he gleaned in 2015 onto his young team. 

“I have the experience of my freshman year, that team’s whole progression from being an okay defensive team and then finishing down the stretch as one of the best defensive teams in the country. That’s one of the main reasons why we won,” Allen said. “But I know that and have that experience so I can tell the guys, look, if we don’t pick up the defense, then these ACC teams are going to crush us.”

Hank Tucker contributed reporting.