The Power of Switching Defenses
Duke’s ability to shift between different defensive looks could provide a March boost
Duke’s shift to a 2-3 zone defense against NC State was crucial in the Blue Devil victory. It doesn’t take a particularly keen eye or in-depth knowledge of the intricacies of defensive strategy to notice that. What it says for Duke’s viability come March Madness is a bit more complicated of a story.
Indeed, it would be quite easy to overreact to this lone data point and argue that Duke should fully embrace the 2-3 zone down the stretch, as it has with recent one-and-done teams (the 2015 National Champions and 2018 Marvin Bagley-led squad played a lot of zone in March). But that would overlook the fact that there are reasons that a vast majority of competitive D-1 teams focus on some version of the man-to-man defense. Specifically, playing a 2-3 zone well requires unique defenders (think of the type of bigs and wings that Jim Boeheim recruits at Syracuse), and the principles of playing a solid zone defense are distinct from the man-to-man principles that most 18 and 19 year old basketball players have focused on throughout their prep careers.
In fact, I’d argue that the Blue Devils’ zone defensive was just good on Monday night, even if the results weren’t always great. There were multiple occasions where the top of the zone, manned primarily by Tre Jones and Jordan Goldwire, was caught over-rotating and yielded an open wing three. Despite that pair being fantastic one-on-one defenders, they don’t possess the prototypical frames for the top of a 2-3 zone, namely the length to clog up passing lanes. And at times, Vernon Carey seemed unsure whether or not it was his responsibility to come up and defend the high post when the ball reached that vulnerable area of the zone.
Yet, the zone was an unabashed success and fueled a convincing Duke victory, which I believe to be driven just as much by the element of surprise from switching up the defense as the way the Blue Devils played in the zone.
Despite the frustration Duke fans often have with Jay Bilas, he was 100% on point during the broadcast when he emphasized how stagnant the Wolfpack offense became when facing the zone. The offensive principles required to beat a zone-defense are unique from beating the aggressive man-to-man that the Blue Devils has played most of the season. While NC State could isolate particular matchups (in particular, Vernon Carey in ball screens) against a man-to-man, such strategies don’t work against a zone. Instead, beating a zone defense requires a more complex scheme to first force the zone to over-rotate, and only then attack the open areas of the floor. Put simply, the offensive plays that work most often against man-to-man defense tend to be flummoxed by a simple 2-3 zone.
And that’s what happened Monday night. Once it was clear that the ball screen offense that worked so well in the first half was no longer a viable option, the Wolfpack stagnated. In perhaps the biggest indictment on their struggles, NC State’s best possessions in the second half only came after timeouts, where Kevin Keats could draw up a specific play designed to break down the zone. But without having prepared for that defense, the Wolfpack players were largely at a loss for what to do against the zone without that specific instruction.
It bears repeating that, despite the Blue Devils’ stellar defensive effort, the Wolfpack’s struggles appeared to be more about the zone itself than anything particularly noteworthy done by the Duke defenders. That, though, shows the power of having multiple defensive looks to throw at an opponent. With teams aware that Duke can play a more than competent 2-3 zone, they’ll have to spend time in the film room and on the court preparing both a man-to-man and zone offense. Add in Duke’s tendency to extend a full-court pressure, and the Blue Devils have the ability to throw three unique defenses, requiring three unique counters, at an opponent. And against less experienced teams, or teams lacking the experience against just the zone defense, the ability to switch between these looks at will has the potential to confuse and stagnate the opponent no matter the preparation.
For what it’s worth, one doesn’t need to look far to see the benefits of this strategy. Georgia Tech has implemented a variety of defensive looks throughout the season, switching from man to zone from possession to possession at times. That’s helped a team that was picked 12th in the pre-season ACC poll, whose recruiting has been hampered by a post-season ban this season, into a tie for fifth place in the conference. Looking a bit farther back, Jon Beilein’s successful West Virginia teams and early Michigan teams would often switch into an exotic 1-3-1 zone for just a handful of critical possessions a game, with the unusual look often able to induce confusion from the opponent and cause turnovers in bunches.
The “hot take” from Monday night is that Duke’s defense looked superior in a 2-3 zone as opposed to a man-to-man, and the Blue Devils should shift towards primarily employing a zone defense. The “smart take” is that every Duke opponent in March will now have to prepare for both a man and zone defense and be able to adjust their offensive strategy within the flow of the game, and Duke should continue to switch between man and zone depending upon the opponent and game flow. When you consider the minimal preparation time between games during the NCAA Tournament, and even more so during the ACC Tournament, that’s an advantage Coach K can exploit.
So don’t be disappointed if Duke doesn’t start in the 2-3 zone against North Carolina Saturday night. But also don’t be surprised if the Blue Devils employ that defense in short stretches throughout the game. That versatility will have to be matched by the Tar Heels, and perhaps every opponent Duke faces in March.