Back in the locker room after losing to N.C. State on Jan. 6, Duke's basketball players were dejected. Some hung their heads. Some looked confused.
The Blue Devils were one of the best teams in the country. Ranked No. 2, they was expected to beat the Wolfpack, even though the game was on the road. But they never got going, and N.C. State controlled the game from start to finish and won 96-85. N.C. State's 96 points were the most Duke had given up all season. And the questions that surrounded them early in the season began to resurface.
Why can't Duke play good defense?
"This isn't cool," a dejected Duke freshman forward Marvin Bagley III said after the game. "This isn't cool at all."
After that game, Duke's players held a 'players-only meeting.' They opened up to each other and talked about how they felt about their recent play.
"We weren't really talking as a team," Duke freshman forward Wendell Carter Jr. said. "We weren't talking on the defensive end."
Duke's captain, senior guard Grayson Allen, spoke up at the meeting. He said they needed to talk more, Carter recalled. They were playing like five individuals, and it appeared on the court that they didn't like each other.
"Everybody really took that to heart," Carter said.
The players came to the conclusion that they needed to pick it up on the defensive end. And that's when it began to turn around.
After Duke's Jan. 10 87-52 win at Pitt, the Blue Devils were ranked 92nd in the country in adjusted defensive efficiency (points per 100 possessions). The Blue Devils were giving up 99.6 points per 100 possessions.
Fast forward to March 14 - 18 games later - and Duke is ranked No. 7 in the country in adjusted defensive efficiency. The Blue Devils now give up 93.6 points per 100 possessions.
Duke took the biggest leap after it decided to use its 2-3 zone as its primary defense before its 66-57 win at Clemson on Feb. 18. It slowed down opponents and made them think before shooting. For four straight games - against Virginia Tech at home, at Clemson , against Louisville , and against Syracuse at home - Duke held opponents to less than 60 points.
"I just think we've gotten to know each other better," Krzyzewski said Wednesday. "And we've stayed healthy - you know Marvin was out for four games - and we've kept growing. We've gotten better. Throughout the whole year we've gotten better to right now, we're the best that we have been all year. Even though we didn't play a really good 34 minutes against Carolina, we're a really good team right now."
Krzyzewski said he likes that because it means his team has bought in and made each other better.
Duke hasn't given up more than 74 points since its 82-78 loss to UNC on Feb. 8.
With the exception of its 81-77 loss at St. John's on Feb. 3, when Krzyzewski called his team out for playing as five individuals, Duke has played well together.
Allen said the stretch where Duke didn't give up more than 60 points was the moment he thinks the Blue Devils realized they could be a good defensive team.
"But once you do that, you have teams that start to scout your defense and so you have to adjust," Allen said. While Notre Dame and UNC did not score much, both teams had some success in finding open men in Duke's zone.
"For us, it's just like man defense you have to adjust to scouting, you have to know how teams are going to play, you have to know their personnel, who's shooting, who's driving, who's passing the ball," Allen said. "We have to do that in a zone too, and that's an important thing that we're still learning."
No. 2 seeded Duke (26-7) will play 15th seeded Iona (20-13) on Thursday afternoon in the first round of the NCAA tournament. Iona ranks 31st in the country in 3-point shooting percentage, and 30th in 3's per game (9.7). Five of its scorers average 10 points or more per game.
Duke knows that its defense will be the key in the NCAA tournament.
"We're just going to look back to that situation we were in, and not let it happen again," Carter said.