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Duke’s zone defense is weird and kind of embarrassing. Will it win a national title?

So, who cares?

NCAA Basketball: NCAA Tournament-First Round Charles LeClaire-USA TODAY Sports

Duke’s defense choked out Rhode Island’s offense on Saturday, so the Blue Devils are going to the Sweet 16. The two-seeded Blue Devils beat the No. 7 Rams in the NCAA tournament’s round of 32 in Pittsburgh, 87-62. The game was every bit that lopsided and more. Duke led, 45-28, at halftime and could’ve won by more if it hadn’t chilled out a bit at the end.

Next up: a matchup with Syracuse in the Sweet 16.

Duke has been in zone defenses for a few weeks now.

During Mike Krzyzewski’s 38 years in Durham, the zone has made occasional cameos. The Blue Devils don’t play it regularly most seasons. But Coach K moved to it periodically during 2015’s national championship season, and he has used it in bits and pieces in the seasons since. They used it to get back into a game against Michigan State back in November.

But over the last few weeks, the zone has become Duke’s primary defense. The Blue Devils started playing the zone full-time (or pretty close to full-time) when they played at Georgia Tech on Feb. 11. They won that game, 80-69, and have stuck with it. The Blue Devils have preferred a 2-3, with two guards near the top of the three-point arc. Here’s that look, which the team kept using through garbage time against Rhode Island:

Duke made the switch when its defense was performing horribly.

There’s no reason for Duke’s defense to ever not be good. The Blue Devils have five-star recruits at four positions and four-star Grayson Allen at the other. They have an athletic advantage against every team they face and a size advantage against many, despite playing with three guards (Allen, Trevon Duval, and Gary Trent Jr.) most of the time.

And yet! Entering that Tech game, the Blue Devils were floundering. They had lost four of their first 11 games in ACC play plus another game at St. John’s, and their defense was the problem. Their point totals allowed in those five games: 89, 96, 65, 81, and 82. In their ACC games up to that point, they’d given up an average of 73.9 points and a 41.1 opponent field goal percentage. That included a 35.3 percent mark on threes and 44.3 percent on twos.

In the 11 games since then, Duke’s been on a good defensive roll. But it’s worth questioning if the Blue Devils are just getting really lucky.

On this run that started with the Georgia Tech game, Duke is 9-2. The Blue Devils have given up an average of 61.7 points. They’re giving up a 38.7 field goal percentage, a nice improvement on where they were during that preceding stretch. All good things!

But this appears to be the result of one thing: Duke’s opponents missing a bunch of threes. Other teams are only making 26.3 percent of their triples against Duke, down from the 35 percent over the previous 11 ACC games that turned up so many defensive flaws. Opponents are actually shooting better on two-pointers, at a 48 percent mark.

This doesn’t explain the Rhode Island win. Duke beat the pants off the Rams. It wasn’t close. But is Duke’s defense really cured, or has it just benefited greatly from a bunch of terrible long-range shooting games? When Rhode Island made seven of 19 threes on Saturday (37 percent), it broke a mind-boggling streak of eight games in which Duke opponents had shot 29 percent or worse from beyond the arc. The national average is 35 percent — AKA pretty much the same success rate teams had been having against Duke until the last 11 games.

There’s a lot we don’t know about three-point defense. A lot of luck is certainly involved, so some evaluators prefer to judge defenses on raw three-point attempts. The idea is if teams are chucking up fewer threes, it indicates the defense isn’t affording many open looks. In the last 11 games, 37.8 percent of shots from the field against Duke have come from the outside. That’s slightly up from 36 percent in the ACC games before Georgia Tech, which, again, are when everyone was under the impression that Duke’s defense stunk. (The national average is 37.5 percent, so Duke is not unusual in this regard.)

My impression from watching a couple of Duke’s games is teams are missing a lot of open threes after some sharp passing against that zone. Whether that’s what’s happening or not, we have no idea if Duke’s going to keep facing bad shooting days the rest of the way.

Duke might pull this off, though. It still has a talent advantage.

We don’t have empirical data on what makes a “zone” team, but not many have won the championship with that as their primary defense, because most teams just play man-to-man. Duke traditionally has, too. While lots could go wrong in the next two weekends, there’s also the chance that lots goes right, and teams keep missing their shots.

Duke’s next opponent, Syracuse, is synonymous with zone defense. It’s also a poor shooting team, hitting only 31.8 percent of its threes as a team on the season. In a battle of zone vs. zone, Coach K’s athletes should have the advantage.

We’re dealing with a small sample size, so betting on anything is risky. But betting on Duke’s talent might be the safest option left in the field.