While high quality play on defense has been a trademark of the Duke program throughout Krzyzewski's tenure, this year's squad - currently ranked second in the nation - has made significant gains from a season ago. Through the first nine games, the Blue Devils are holding opponents to just 63.9 points and 8.7 assists per contest, as well as an impressive 38.3 shooting percentage from the field. The team has already matched a Coach K-era record by limiting five of its nine opponents to under seven assists in a game. Duke also set a record by allowing just 22 assists in a four-game stretch from Nov. 23-Dec. 1.
Those numbers are directly reflective of Duke's consistent ball pressure, which has disrupted some of the top offenses in the country in wins over top-five foes Kentucky, Louisville and Ohio State.
"Defense is just about fighting," said junior guard Tyler Thornton. "A lot of offensive-minded players, they don't want to use too much energy trying to get the ball or trying to get open. So as a defensive player, I try to make those guys use more energy than they want to in order to get their shot off. That way, they take more difficult shots or they just don't have the energy to take a solid shot."
Some of Duke's most notable gains this season have come at the guard position, where Thornton and sophomore Quinn Cook have contributed solid minutes defensively. Both rank among the league's leaders in steals per game and have paced the Blue Devils to an average of 14 forced turnovers a game - up from a 12.6 average in 2011-12. The team has also forced at least 10 turnovers in all but one contest, coming up with 15 against then-No. 2 Louisville to put away the Cardinals in the closing minutes of the Battle 4 Atlantis championship game.
Thornton has developed into one of the Blue Devils' defensive leaders by virtue of his tenacity and ability to unsettle opposing ball handlers. The team's leader in steals this season, Thornton provides a spark on defense, whether by initiating turnovers, cutting off passing lanes or drawing charges. He says Duke's coaching staff has been instrumental in teaching him how to apply effective ball pressure throughout an entire defensive possession.
"There are a lot of different schemes and tricks here and there that our coaches have told us since I've been here, and it's definitely helped on the ball, off the ball," Thornton says. "It just wears other teams down. Their main ball handlers can't really run the team because they're focused on not turning the ball over or they're trying to get open on the wing. It disrupts the other team's offense when you apply a lot of pressure."
Cook, too, has matured greatly in his defensive efforts. The second-year point guard, who joined the Blue Devils' starting lineup in the third game of the season, attributes his improvements on defense to being in better physical condition and keeping active hands to hold ball handlers accountable. Cook also says he has honed in his defensive approach by thinking about what effective defenders do to bother him on the other end of the court.
"Being a point guard, when a guy is picking me up full court and making me turn my back instead of me focusing on our plays, I'm very uncomfortable," he says. "I try to use that against other point guards - make him uncomfortable, turn his back a lot, make it hard for him to communicate with his offense while he's bringing the ball up the floor."
Cook also credits Duke big men Mason Plumlee and Ryan Kelly with helping Duke protect its basket. Kelly is among the ACC's top 10 in blocks per game and leads the squad with 19 so far this season, while Plumlee is the conference's leader in defensive rebounds per contest. Both players' abilities to contest shots have also been a big part of the 38.3 percent shooting percentage Duke's opponents have been held to in the first nine contests.
With new additions to the lineup in redshirt freshman Alex Murphy and rookies Amile Jefferson and Rasheed Sulaimon, the Blue Devils also now boast a good deal of size on the perimeter, another factor which distinguishes this team's success on defense. Junior forward Josh Hairston says he spent long hours in the gym and weight room this summer working to make his presence felt on defense, and Sulaimon has demonstrated an ability to create on both ends of the floor.
"The old adage is 'defense wins championships,' and we really took that to heart through the offseason and so far this season," Sulaimon says. "The main focus on any Duke team is defense, and that's something I really take pride in."
While the Blue Devils' offensive numbers alone are staggering, Krzyzewski hopes to see his team continue to fight on defense. He has instilled in his players that it takes all five - and not just the player on the ball - to make the whole scheme work and carry Duke on to the next.
"We've played some great scorers and it's not just guys like [Ohio State's] Deshaun Thomas versus Ryan Kelly," Cook says. "Deshaun saw Ryan Kelly and then four other Duke players on him. He didn't see that all year. All five of us have each other's backs. If we communicate, we talk and we execute the game plan, we're going to be a great team."