-Jim Root
Welcome to Part 2 of my exceedingly nerdy dive into why zone usage is declining across all of Division I hoops – if you missed Part 1, check it out here. Several of the conclusions/conjectures will be referenced below, so you may find it helpful. Part 2 will delve more into the repercussions of playing zone and how it affects the offense, plus a bonus section that stratifies the national trend further by conference. Enjoy!
For any of you that also read/follow Hoop Vision (and I’m guessing it’s a lot of you), you’ll surely know that one of Jordan Sperber’s most harped-on tenets is the concept of tradeoffs. In the context of my analysis here, that means that as a defense, if you’re going to take something away, whether that be pick-and-rolls, post ups, or another offensive tactic, you have to be willing to give up something else. You can’t eliminate everything, so the smartest approach is really one of two options:
Have a well-defined scheme that you can teach from year-to-year, one that dictates the playing field for the offense and funnels them towards your strengths/away from your weaknesses. Though all vastly different, this applies to Tony Bennett’s pack line, Jim Boeheim’s 2-3 zone, and Bob Huggins’ Press Virginia (though he’s moved away from it somewhat) – get great at something and force the offense to counter.
Determine what your roster is best equipped to do on a year-to-year basis and plan accordingly. Many coaches opt for choice #1 and recruit players specifically capable of playing that scheme, but others operate on more of a “take the best players available” and adapt the approach based on who they get. Huggins lessening his use of the full court press is actually a strong example of this; another would be Coach K audibling to a full-time 2-3 zone in 2017-18 when his team couldn’t guard anything in man-to-man.
Either way, the decision revolves around taking something specific away. Boeheim and the others like him that go all in on zone are making a conscious choice: cover areas instead of players, forcing opponents to attack in an entirely different way than they are generally accustomed to doing.
To dive into the decision-making process that goes into playing zone, we’re going to use Synergy Play Type data from 2019-20. A typical Synergy page classifies plays as one of 11 general (and largely self-explanatory) types, listed below. Per that data, here are the average occurrences of each play classification in 2019-20 against all 353 Division I teams:
In Part 1, I referenced that seven teams played zone more than 75% of the time – those teams were Syracuse, Merrimack, Eastern Michigan, Washington, Tulane, Northern Kentucky, and Hofstra. Against just those teams, look how the tendencies change compared to the average:
Unsurprisingly, we see a huge rise in Spot Up, Cut, and Offensive Rebounds, while both Pick-and-Roll types, Post Ups, Isolation, Handoff, and Off Screen all plummet. This isn’t a groundbreaking revelation by any means, but it is indicative of the choice a coach makes when playing zone, consciously accepting the offensive approach that foes will have to take.
To better illustrate that, here’s two of those teams (Syracuse and Merrimack) and their individual Synergy play type breakdowns on defense, with the frequency and frequency rank for each play type; check out the obvious similarities between them. It’s almost like reading The Matrix’s “digital rain” lines of code – the data doesn’t explicitly say the word “zone,” but it reads like it if you look at enough of these:
For comparison’s sake, here’s two pack line teams (Virginia and Liberty). Much like the zone teams, you can clearly see the trends that develop for a specific genre of defense – take away transition, offensive rebounds, cuts, and other miscellaneous plays:
The specific collection of play types that zone allows is why committing to zone full time is risky: those three (Spot Up, Cut, and Offensive Rebounds) are all inherently more efficient than the intrinsically “man-to-man” plays, which all but disappear. Here’s the average PPP for each play type – the difference is stark:
That means playing zone is, at the most basic level, intentionally conceding more efficient shots. Of course, teams that consistently practice and play zone can tweak things to make these chances more difficult. For example, 2-3 zone teams like Syracuse and North Florida have sometimes extended to an alignment that more closely resembles a 4-1, spreading four defenders across the perimeter and leaving just one shot-blocker patrolling the paint.
That brings me to one of my theories in Part 1 on why zone is declining: teams don’t practice it as much. If a coach knows that his team isn’t prepared to play zone in such a way that challenges shots and adjusts to how the offense is attacking, he’s not going to be inclined to just trot a zone out there for the sake of doing so. Instead, he’ll focus on man-to-man and drilling his team to try and master that, forcing pick-and-rolls, isolations, and other less efficient play types.
Also back in Part 1, I speculated that part of the reason for playing less zone was the rising skill level across the sport. More players can shoot, and more big men have the patience and IQ to make quality reads at the high post. But with 357 teams and 32 conferences, that rise in skill level isn’t necessarily linear across the board. Certain leagues attract different types of players, and that creates opportunity for coaches to test the skill level of their opponents. Much like how pressing is more difficult against higher-caliber guards, zoning against better shooters and passers is more of a high-risk proposition.
(Side note: this is why every middle school dad/coach wants to play zone – young kids just don’t have the necessary skillsets to take advantage of what the zone offers. But if you’re a youth coach, please, don’t do this all the time. Let the kids learn to play man-to-man, it’s irrefutably better for their hoop futures.)
I went through the team-by-team zone data to see if the divide in usage had a big conference/small conference split – here’s the top 10 conferences:
The average zone usage for these teams (121 of them) was 9.9%. That massive Pac 12 drop in 2019-20 is directly attributable to Stanford, USC, and Cal going to mostly man-to-man; I wrote about the first two teams here. Switching focus to the other 22 leagues, here’s that same conference breakdown:
That group of 236 teams played zone on an average of 13.1% of possessions, nearly 33% higher than the power conference squads. This supports the theory that zone is more tenable in smaller leagues, as does the fact that all six conferences that played zone more than 20% of the time were mid-majors (or low-majors). Similarly, six of the bottom 11 zone users were power conference/high-major.
Regardless, though, the general trend of decline is present at both levels:
Sadly, the homogenization of college basketball is likely to continue. Analytics have shown coaches and teams where the most valuable shots are, and most man-to-man schemes simply do a better job of taking those shots away. Zone will still have its place in the game for teams that embrace that as a full identity, but the number of teams that try to mix in some of both – be it high-major or mid-major – is almost certainly going to keep dwindling. Enjoy the quirky zone schemes that do exist, folks, because that may be all we have soon.