Switch 5 (Part 1): What Tracking-Era Numbers Reveal about the NBA’s Hottest Trend
A seemingly offensively-motivated free agent signing by an NBA contender during the 2021 offseason developed into a storyline that only a handful of years ago would’ve sounded ludicrous.
When Utah signed veteran forward Rudy Gay to a two-year deal in August 2021, one of the more prevalent takes on the situation was Gay’s potential ability to play “small-ball 5” for the Jazz in order to give them more defensive versatility, especially in the playoffs.
The merits of this storyline can be debated, of course. After all, the Jazz did have arguably the best defensive player in the NBA playing the center position. But the reality is the massive changes in NBA offense over the past decade have forced teams to adjust by trading height for quickness.
Hence, the “Switch 5” was born.
A Note about Tracking Data
We can denote the 2013–14 season as the official beginning of the tracking era. That’s the first NBA season in which league-wide tracking data became available through Second Spectrum.
The addition of tracking stats was a welcome one. Box scores can only tell us so much, and given how complex the game of basketball is, there is plenty of room for additional data to be compiled.
One of the more useful subsets of tracking data that Second Spectrum introduced is ball screen data. Instead of having to manually track how successful a ball-handler is against hedges, or how awful a center is at guarding high pick-and-roll, it has been automated for us (to a degree).
Before I dive into the analysis, I want to reiterate the main component of my analysis: players who are playing the “5” position switching a ball screen. I understand that switching happens at other positions and that defining a “5” can be an inexact science. For the purposes of this research, I am generally relying on Second Spectrum’s filter titled “Screener Position (by Matchups).” That being said, there are some instances where I manually select players, but I will mention that when necessary.
Okay, let’s see some graphs
Utilizing ball screen data, the first question I was interested in was simply how much more switching is occurring today compared to the beginning of the tracking era.
I calculated the percentage of screens that a center switched onto the ball-handler after a ball screen (aptly named “Switch Rate”) for each of the last eight seasons:
For the first couple years of the tracking era, the league was looking at a 4% Switch Rate. The past four years the average has hovered between 8 and 10%.
I also threw in a potential cause of the switching craze: the rise of ball screen 3’s. Ball screen 3’s was one of the first things I thought of because, in addition to switching, it is something that has become more routine for NBA teams and players over the last decade or so. Hypothetically, one of the counters to pull-up 3’s is for the defense to switch. While the numbers track somewhat, there definitely seems to be more to the story.
But first, let’s split up the data between regular season and playoffs:
Oh baby. One thing is clear: teams switch much more in the playoffs than they do in the regular season, even going back to the beginning of the tracking era. Another thing to note, though, is that the growth of switching hasn’t been linear. For instance, 2017–18 is the highest on record because the switch-addicted Rockets made it to the conference finals and played a 7-game series.
Now that we’ve established that switching has seen a significant rise in popularity as a defensive strategy, let’s figure out why.
Back to the Second Spectrum well, where we can filter by ball screen defense and find out what happened during those plays when a switch occurred.
Since 2013, NBA teams have seen the following trends when playing any P&R defense other than switch:
- Ball-handlers shooting MORE
- Ball-handlers passing LESS
- On-ball defenders dying on the screen MORE
Since 2013, NBA teams have seen the following trends when switching P&R:
- Ball-handlers shooting LESS
- Ball-handlers passing MORE
- On-ball defenders dying on the screen LESS
The only trend that didn’t reverse? How effectively ball screens are guarded.
This past season, teams had roughly the same DER when switching ball screens as opposed to utilizing a more traditional P&R coverage.
Conclusion: Teams started switching more because ball-handlers became more adept at exploiting ball screen coverages. Screeners were giving their ball-handler a serious advantage by setting a screen and the other team not switching.
Shot Quality
To drive the point home, I wanted to take a look at shot quality, which has become an increasingly popular topic in the analytics community.
For the purposes of this analysis, I defined big and small lineups as follows:
Big Lineups = Lineups that feature 1 or more center(s)
Small Lineups = Lineups that feature 0 centers
Again, I should note that Second Spectrum’s “Center” label isn’t always perfect. For instance, it considers Bobby Portis a “Forward”, although many would argue Portis is more of a center and one that would likely be a perfect example of the type of center that would be played off the floor in the playoffs due to an inability to switch.
Nevertheless, we march on.
Though the data fluctuates a bit due to small playoff sample sizes, teams have consistently been getting better shots in the playoffs since 2013 regardless of lineup type.
More notably, we can see that prior to the 2015–16 season, big lineups were really holding down the fort in terms of shot quality defense. With these numbers in mind, think about the basketball discourse 10 years ago — why would you ever play small?
One thing to note about that outrageous 2017–18 number is that the Cavaliers made the Finals using a lineup with Love at center, which, uh…. did not go well:
Taking out Love lineups, that shot quality number drops to around the same number as what the big lineups surrendered. As for 2021–22, Draymond at center was surprisingly rough on defense, as was the Maxi Kleber small-ball groups for Dallas.
Where we go from here
The purpose of this introduction was to lay down some basic facts about the switching era. We’ve established that switching has become significantly more popular, it happens much more often in the playoffs, teams likely started switching more to mitigate the advantages that ball screens created, and while switching may result in giving up better shots, teams are having a hard time playing any defense successfully in the NBA.
Next, we want to see how switch 5 lineups differentiate from traditional lineups from a statistical standpoint — stay tuned for Part 2.