How Duke fixed its defense in the NCAA tournament By Rob DausterApr 1, 2015, 2:15 PM EDT Share this:Click to share on Facebook (Opens in new window)Click to share on Flipboard (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on Reddit (Opens in new window) 3 Comments (AP)Prior to the start of the NCAA tournament, I did not think that Duke belonged in the same conversation as Kentucky, Wisconsin and Arizona when it came to talking about national title contenders.They were as good as anyone on the right side of the bracket — in that same conversation as Gonzaga, Virginia and Villanova when it came to the favorite to get to the national title game — but the consistent lapses that Duke had on the defensive end of the floor were too much to ignore.We’ve been over those defensive lapses quite a bit in this space, but to make a long story short, Duke’s perimeter defense was far too porous, they had no intimidating shot-blocking presence at the rim and their ball-screen defense was, to put it nicely, really, really bad. Entering the NCAA tournament, the Blue Devils were right around 60th in adjusted defensive efficiency, according to KenPom.Things have completely changed in Duke’s four NCAA tournament games. Duke has yet to allow more than 0.89 points-per-possession in any of their four games, posting defensive numbers that are more or less on par with what Kentucky has done all season. Seeing the Blue Devils dominate Robert Morris and San Diego State on that end of the floor is not all that surprising, but watching Utah and Gonzaga, who entered the Elite 8 as the nation’s fourth-most efficient offense, struggle against these Blue Devils was quite unexpected.Duke now enters the Final Four ranked 18th in adjusted defensive efficiency.What happened? How did Duke go from a defensive liability to a team that is very tough to score on? I watched every possession that Duke played defensively last weekend in Houston, and here’s what I can come up with:Quinn Cook’s ability on the ball makes Duke very good vs. teams with dominant PGs: One of the most impressive in-season improvements that we’ve seen this year is with Quinn Cook, a guy that has gone from often being a defensive liability to one of the nation’s better on-ball defenders. He’s certainly the best that Duke has in their back court, and he’s proven it over and over again. He took away Jerian Grant and Marcus Paige in wins over Notre Dame and North Carolina this season, and he did much of the same to Kevin Pangos and Delon Wright this weekend. Wright was 4-for-13 from the floor with just two assists and two turnovers, while Pangos was 2-for-8 from the field with no assists and three turnovers.“I’ve always taken pride in outscoring whoever I was matched up with,” Cook told the News & Observor. “I’ve never taken pride in shutting someone down. I’ve learned to like playing defense.”Both Wright and Pangos are key facilitators that create a ton of scoring chances for their team and run their respective offenses. Cook’s ability to give them fits was a major reason that Duke’s defense was so effective.Justise Winslow is a bad man: Winslow is an awesome defensive player, and his particular skill set makes him so valuable to the Blue Devils given the way they like to defend. He’s big, strong and long enough to defend most power forwards at the college level, but he’s also quick and athletic enough to defend just about any perimeter player. What that means is that when Winslow is at the four with three guards on the floor — the starting lineup that Coach K has been using since late February — they can switch 1-through-4 defensively while staying in a man-to-man defense, which is an easy way to take an opponent out of what they want to do offensively.Duke’s 2-2-1 press caused some problems: Duke showed a 2-2-1 press against both Utah and Gonzaga in certain situations — usually after a made free throw — that caused some problems for their opponents. A 2-2-1 is not like ‘Havoc’ or ’40 Minutes of Hell’, it’s used more to chew up clock and to bait impatient teams into throwing dangerous passes. Both the Utes and the Zags had a couple of turnovers when Duke threw the 2-2-1 at them.The Dome probably helped, too: Call me a hater if you must, but both Gonzaga and Utah missed a number of jumpers that they usually hit. Both the Utes and the Zags shot better than 40 percent from beyond the arc this season, and combined, they were 6-for-26 from three in Houston. This is the same dome where Butler and UConn had that horrid, 53-41 national title game. Maybe there’s something to that?As did Jakob Poeltl and Przemek Karnowski: Neither Poeltl or Karnowski can shoot from the perimeter, meaning that Okafor could just hang out in the paint and provide help. He’s not a great shot blocker, but when he’s standing in front of the rim instead of chasing big men that can shoot out to 15 feet, he does have an affect.But mostly, it’s just execution: After watching around 120 possessions of Duke’s defense from last weekend, I can definitively tell you that Coach K is not re-inventing the wheel here. This isn’t a gimmick, it’s not him shocking the world with a 2-3 zone like he did at Louisville. It’s not as simply explained by shooting in the Dome or that the matchup, one with a dominant point guard that Cook can takeaway, was good for the Blue Devils.As weird as this sounds, the biggest change may simply be that Duke is just playing better defensively.It’s little things, simple executions on defense that they had issues with earlier in the year. They’re communicating better on their switches. For example, if a guard gets switched onto a power forward, he’s able to front in the post and he’ll have help on a pass over the top. This is such an important part of what Duke does defensively. They play an extended man-to-man and have been switching all exchanges 1-through-4, meaning that any screen involving two players that aren’t the opposing team’s center is an automatic switch. This makes it very difficult for an opponent to run their offense and puts a priority on the ability of playmakers in 1-on-1 or ball-screen actions.Which brings me to my next point: They’re doing a better job icing side ball-screens and forcing the ball-handler to one side on high ball-screens. They’re also doing a better job of playing to the scouting report, something as simple as going under a ball-screen if the dribbler is a poor shooter. This was the biggest issue for Duke earlier in the season. They would force a team into ball-screen actions and then get lit up because they couldn’t defend those ball-screens.Well, now they are.Could this really be as simple as Duke finally figured out how to play defense?