Duke hasn’t exactly been itself since the start of ACC play.

Now .500 in their conference, the Blue Devils’ two ACC wins have been nail-biters. They led Georgia Tech by only one point at halftime during their contest, and they trailed 65-64 to Virginia with 38 seconds remaining. Duke’s two losses were especially tough, as it failed to overcome Notre Dame in the last seconds of its first league game before being crushed by double-digits against Clemson one week later. Although unpredictable, these losses point to the fact that after this year's expansion the ACC is a tougher conference than it ever has been before.

“Our conference is a lot tougher with the new additions," senior guard Tyler Thornton said. "The teams around the conference are older, very strong, very athletic. Every game will be a battle no matter who we're going to be playing, especially because we're Duke, so everyone's going to give us their best shot."

But head coach Mike Krzyzewski points to a different reason for his team’s struggles: himself.

“We haven’t been at our best since the start of conference play, and I haven’t been at my best since Christmas,” Krzyzewski said. “That’s my responsibility. We’ve been knocked back… because sometimes things that occur that are human.”

A giant in the coaching world, Krzyzewski had a brush with his own mortality when his brother Bill passed away Dec. 26 at the age of 71. The Blue Devils were without their coach until he rejoined them just before their contest against Notre Dame. Duke then opened conference play with a 1-2 record for the first time since 2007.

Krzyzewski, however, does not blame his team for the Blue Devils' shortcomings—instead, he shoulders the burden.

"You could make any [assumption], like we didn't do this and didn't do that, but it's on me, those first three games," Krzyzewski said. "Everything is on me, and part of it is not seeing some things."

Against Virginia, Krzyzewski saw the Blue Devils turn around and play with a type of intensity that had been missing early in conference play. Led by Rasheed Sulaimon's 21 points and Amile Jefferson's first career double-double, Duke was able to withstand a late surge by the Cavaliers to snag their second ACC victory.

"It was a battle," Krzyzewski said. "We played with so much heart tonight, and it was our best game as far as that goes because we beat a really good team... Today we weren't knocked back."

In Duke's losses to Notre Dame and Clemson, Sulaimon was essentially a non-factor, tallying only six points against the Fighting Irish and two against the Tigers. But he was resurgent against Virginia, with his most important basket coming with 19.2 seconds left in the contest. After Jefferson snagged the rebound off Rodney Hood's missed jumper attempt, he found Sulaimon waiting in the corner, where his shot bounced off the rim and into the basket.

"As soon as Amile got the ball, I made myself available," Sulaimon said. "He was looking for me as well. He trusted me, he passed it to me, I shot it with confidence and I thank god that it went in."

Despite the stellar play of the sophomore duo, however, the Blue Devils' victory was a true team effort. Krzyzewski created what were essentially two different lineups: his starters, consisting of Jefferson, Hood, Jabari Parker, Quinn Cook and Matt Jones, and a combination of five bench players, which he substituted into the game every few minutes. His platoon lineups, he said, stemmed from watching his team more carefully in recent practices.

"I'm not saying we're going to platoon like that all the time, but we're going to play more guys," Krzyzewski said. "I've had to get more observant with my team."

Redshirt sophomore Marshall Plumlee logged 12 minutes, his second-most of the season, while Jones, in his first career start, was a needed defensive presence. Even freshman Semi Ojeleye, who had previously played only one minute since Dec. 31, made the most out of his two minutes in the game, notching two rebounds.

And to Krzyzewski, the team effort on the court represents a new, team effort off the court.

"We were collectively together tonight for the first time in a couple of weeks," he said. "My kids played their hearts out tonight, and we're just going to keep moving on."

As Krzyzewski dealt with his personal loss, Duke had fallen in the polls and standings. The Blue Devils will only face tougher ACC competition as their season goes on, but Duke's victory against the Cavaliers showed Krzyzewski that his team is different than it was even two weeks ago.

And as Krzyzewski continues to heal while he prepares his team for the meat of the season, he trusts in his team's heart to guide them along.

"I can do better for my team," he said. "But tonight my team was marvelous, and I love them for the way they played."