May 2, 2014; Dallas, TX, USA; Dallas Mavericks forward Dirk Nowitzki (41) shoots over San Antonio Spurs guard Tony Parker (right) during the game against the San Antonio Spurs in game six of the first round of the 2014 NBA Playoffs at American Airlines Center. Dallas won 113-111. Mandatory Credit: Kevin Jairaj-USA TODAY Sports
In my last post, I looked at the offensive styles of back court players based on where on the court they took their shot attempts using a technique called cluster analysis. However, it is not only back court players that have different offensive styles. The stretch big is sort of a thing these days, there are still many bigs that rarely shoot away from the paint, as well as mid-range specialists like LaMarcus Aldridge or Brandon Bass.
Based on my initial principal component analysis there were three strong sources of variation in shot selection among power forwards and centers, using NBA.com data for front court players over the last four years; shots at the rim pitted against three point shots and mid range shots. Shots in the paint outside the restricted zone and corner threes did not show significant independent grouping power.
The variation along the second grouping of mid-range shooters was much stronger than for back-court players. Virtually all guards and wings attempt some shots from all three zones, it is just a matter of degree and emphasis, while a majority of bigs almost never shoot threes and a plurality barely shoot anywhere outside the restricted zone. Consequently, the cohesion within the clusters was higher than the back court clusters as was the separation between the clusters.
The three groups identified by the cluster analysis, that I named Paint Bigs, Mid-Range Bigs and Stretch Bigs. Over the four years of the study 47% were grouped as Paint Bigs, 36% as Mid Range Bigs and only 17% as Stretch Bigs. The table below has the group average shot attempts by the relevant zones.
So, In the Paint Bigs, the largest group, on average took took 82% percent of their shots in the paint and virtually no threes. Stretch Bigs, on average took just over forty percent of their shots from beyond the arc, a huge contrast. Mid Range Bigs were somewhere between the the other two groups in the paint but also took virtually no threes, on average, and almost twice as many mid range shots as any other group. The visualization of 2014 bigs below gives a decent picture of how the clusters operate with a few names attached:
We can take the analysis one step further by getting the stats averages for the different clusters. The cluster are indicative of different playing styles over all with Paint Bigs showing up as more traditional front court players with higher scoring efficiency, lower usage, more offensive rebounds and fewer assists. Mid Range Bigs are the least efficient scoring with Stretches in between. One of the less surprising findings is that, like the back court cluster, the farther a player tends to stand from the basket the fewer offensive rebounds he gets, with Stretch Bigs having an offensive rebound rating just over half that of Paint Bigs.
One additional note with shooting clusters on the bigs is that grouping centers and power forwards shows a real difference by position, much more so than back court players. Power forwards are much more likely to be in the ‘Stretch’ group as well as the Mid Range Bigs look group, splitting 36% Paint, 27% Stretch and 37% Mid Range. On the other hand, for centers Stretch shooters were rare, with centers split 60% Paint, only 6% Stretch and 34% Mid Range. However, within positions the trends among shooting groups held very similarly.
The shooting percentages also once again show that the shot selection is at least in part by necessity, as Paint Bigs struggle shooting away from the basket and Mid Range Bigs tend to shoot poorly from beyond the arc.
The list of top front court players by shot attempts in 2014 shows that the shot selection isn’t detriment of value, with some of the best players adopting different styles. It also shows the complications of categorization as Basketball Reference counted both LeBron James and Carmelo Anthony as power forwards, whereas they had both been considered small forwards in previous seasons (where James will no doubt play again this year alongside Kevin Love). This is the list of the front-court players with at least 900 shots in 2014 with their assigned cluster and shooting location breakdowns.