'The Defensive Dilemma' Part 1: To Zone or not to Zone

- Matt Cox

We have officially reached the 1 month 'mile marker' of the 2016-17 college basketball campaign, which means most schools already have ~7 regular season games under their belt. For the exception of injuries and other anomalies, we now have a large enough sample size needed to assess who all 351 teams really are - Is UCONN actually bad? (yes) - Are Creighton and UCLA for real? (yes).  

While tracking how teams are trending from a win/loss perspective is no doubt important, I've chosen to dive a little deeper into understanding why certain squads have both overachieved and underachieved so far this year, relative to their preseason expectations.  And since I'm a moderate believer in the cliche saying of 'Defense wins championships', I hereby present to you: 'The Defensive Dilemma'.

Using a 'top-secret' database we here at 3MW are blessed to have access to, I compiled a spreadsheet that tracks the defensive tendencies of all 351 teams over the past four years, including the first 6-8 games of this season.  This data 'gold mine' was used to answer two questions that are core to every team's defensive identity:

  1. How often do you play man-to-man vs. zone?  [focus of part 1 - this article]
  2. How often do you full-court press vs. pick up behind half-court?  [stay tuned for part 2]

Here in Part 1, I will specifically tackle the first question above, which will reveal not only which team's tend to prefer man vs. zone, but also whether or not those tendencies have changed in recent years. - specifically from last season to this season. For teams that did exhibit a noticeable shift in their defensive philosophy, I wanted to understand why this change was made, which can essentially be broken down into two primary reasons: 

  1. A coaching change: A new head coach brings a fundamentally different defensive mindset than the prior coach
  2. A change in coaching mindset: The same head coach fundamentally alters how his team defends, which may be due to a change in personnel or simply a change in defensive mindset 

Before getting too deep into this analysis, let's provide some context for how often the division 1 landscape chooses to play man vs. zone defense in general.  I included a distribution of all 351 teams by quartiles, for those of you stat nerds out there that wanted to see how the data skews:

The way to interpret this chart is as follows: out of every single possession that's occurred in every game this year, approximately 18%** of them have featured an offense trying to score against a zone defense. A more meaningful interpretation may actually come from looking at the quartile figures, which for 2016-17 implies that half the teams in all of division 1 basketball have played zone 10% of the time or less (2nd quartile - the median) and 75% of teams have played zone 24% of the time or less (3rd quartile).   So looking across all four years, it's clear there hasn't be a significant shift in defensive style, BUT you do notice an ever-so-slight decline in the amount of zone being played this year, relative to last year.  And though yes, it is only a marginal dip, I'm actually somewhat surprised these numbers haven't trended upward at all...

My hypothesis was that because there have been some widespread struggles in adjusting to the new defensive hand-checking rules that were instilled prior to the beginning of last season, some many coaches may be incentivized feature more zone looks (whether it be a standard 2-3 or an extended pressure 1-3-1) in order to reduce meaningless fouls on the perimeter and limit easy dribble penetration.  However, given the way the data is currently trending, my [dumb] theory appears to have been disproved - at least thus far. 

** this number is a little skewed because it is not adjusted for tempo.  Still, it is probably very close to the real figure.

Now let's take a look at which teams are this season's top  'Zoners' and 'Man-ners'; that is, which teams have predominantly played zone and which teams have predominantly played man-to-man over the first 6-8 games of the year.  The first graphic below shows the top 'Zoners' and the graphic directly below that reveals the top 'Man-ners':

Using the exhaustive heatmaps above (I'm only showing 36 teams here), I hand-selected a sample of schools who are in the midst of a major defensive change this year.  A few examples above are easy to spot with my beautiful color coding - just look for teams with large deltas from the 2015-16 column to the 2016-17 column (see Nicholls St., Northwestern and Stanford).  My intention was to answer one simple question - is this change actually working?

From examining the data at an aggregate view, so far this year, there appear to be more instances of success for teams who shift to a more man-to-man focused defense, compared to teams that try play more zone.

Below are a few examples of schools who are currently 'rolling with the changes' as their defensive blueprint undergoes a noticeable makeover.

Teams shifting to man-to-man...

Team: Stanford
Reason for change: New coach
Is it working? - Yes
Despite an unprecedented dominance of the NIT, Johnny Dawkins was ousted this offseason in Palo Alto, paving the way for ex-UAB head coach Jerod Haase to take over the helm.  Prior to his four years at UAB, Haase had spent his entire collegiate coaching career attached to Roy Williams as a long-time assistant at both North Carolina and Kansas over a 13-year span.  The Tar Heels have been predominantly a man-to-man defensive team under Williams, which likely explains Haase's philosophical preference for man himself.  While his teams at UAB did mix and match with some occasional zone schemes, Haase appears to have returned to the man-to-man defensive roots instilled in him during his time under Williams.   So far this season, Stanford has played zone on less than 1% of all their defensive possessions, a significant drop from 40% of the time last year under Dawkins.  This shift to man-to-man, combined a solid core of veteran players returning from last season, has jolted the Cardinal into a bonafide top-30 defensive unit, a major jump from their 92nd nationally ranked defense a year ago.

Team: Northwestern
Reason for change: Better personnel
Is it working? - Yes
Unlike Stanford, Northwestern did NOT make a change at head coach this offseason, bringing back Chris Collins for year number 4 as their leading man in Evanston.  Despite two straight seasons of playing a fairly significant amount of zone, Collins appears to be transitioning his defense to an exclusive man-to-man scheme, which aligns with the philosophy of his former coach and boss, Coach K.  After playing zone on 43% of all defensive possessions last season, the Wildcats have played zone only a handful of times this year.  The only real explanation for this change is the new dose of length and athleticism Collins now has at his disposal with Vic Law back from a season ending injury last year and sophomore Derek Pardon now emerging as a legit interior defender. While it's too early to make a final judgment on how effective the switch to more man-to-man has been, Northwestern currently sit 36 spots higher in kenpom.com's overall defensive efficiency ranks than they did a year ago.  By no longer playing a conservative, pack-it-in type of zone, the Wildcats are doing a much better job at limiting open looks from the outside, which perfectly complements their already stout interior defense (ranked 33rd and 12th in 2-point% defense and block% respectively).  This typically forces opponents to settle for less efficient midrange jumpers - a big reason why their eFG% defense currently ranks in the top-30 nationally.

Other Notable Team(s)...

Team(s): Mississippi St. & Missouri St.
Reason for change: Better personnel/reaction to last year struggles
Is it working? - Too early to tell
Mississippi St. and Missouri St. have both forced more turnovers this season on a per minute basis than they did last year, but neither team has been challenged by upper-level competition in their non-conference slate, which could very well be skewing the early season success.  Given both teams' overall defensive efficiency has only marginally improved this season, only time will reveal whether this increased focus on man-to-man by Ben Howland and Paul Lusk was in-fact the right move...  

Teams shifting to zone...

Team: South Dakota St.
Reason for change: New Coach
Is it working? - No
As reigning champs of the Summit League, South Dakota St. once again entered the season with relatively high expectations, especially with an emerging star in big man Mike Daum anchoring the paint.  However, under first year head coach TJ Otzelberger, the Jackrabbits have been a major disappointment for the better portion of non-conference action, currently sitting at 4-7 overall (2 of those wins were against non D1 opponents).  While an ice-cold shooting slump to start the year has certainly hampered the offense, it's been a letdown on the defensive end that has compounded the struggles for SDSU.  Otzelberger has gone away from the traditional man-to-man structure that his predecessor Scott Nagy embedded in this program over 20 years ago, which was consistently effective at defending the 3-point line - an area where the Jackrabbits are currently being gashed this year.  With the significant shift to zone (42% of all defensive possessions this season, compared to 1% and 2% the previous two years), the Jackrabbits are surrendering the 2nd most 3-point attempts in the entire country, and unfortunately for Otzelberger, those shots are falling at an alarming rate (38%).  And even when those long range bombs aren't falling, the less structured zone scheme is allowing way too many 2nd shot opportunities.  The Jackrabbits have plummeted from a top-25 defensive rebounding unit last year to the 227th ranked defensive rebounding team this season, something that must be fixed if Otzelberger has any hope of getting this season back on track.

Team: Penn
Reason for change: New Coaching Philosophy
Is it working? - Yes
While the wins and losses so far this season won't show it, the Quakers are quietly taking a major step forward in year 2 of the Steve Donahue era at Penn.  Despite sitting at 3-4 on the year, Penn has shown some flashes of competence against some upper tier teams (see 12-point loss @ Miami and 8 point loss @ Temple), and have already climbed 70 spots in kenpom.com's overall rankings since the start of the season.  While it's plausible that the high rate of zone Donahue has shown this year (56% of defensive possessions, compared to 13% last season) is due to the tough non-conference slate (they also played Villanova), it's clear that the shift away from man has certainly been effective.  Even in the 20+ point loss to Nova, the Quakers turned over their Philly rival 17 times, and caused Miami to cough it up 16 times as well.  As it stands today, Penn is sporting a top-25 nationally ranked steal rate, a laughable improvement from a bottom-50 ranked defensive turnover rate last year.  I'm curious to see how this stat trends once conference season rolls around to see if Donahue reverts back to playing more man-to-man against smaller and less athletic squads in the Ivy.

Stay tuned for Part 2 of 'The Defensive Dilemma', which will focus on a similar type of analysis, but for full-court pressure style of defenses (brought to you as always by DJ Dimes).