Ok, I am not really going to answer that definitively. But, at first glance, it doesn't look it.
This is the third in my series on shot location in the NBA. The first two looked at guards and small forwards. In this one I grouped Centers and Power Fowards together as 'bigs.' I used a Two Step K-Means cluster anaylsis to group Bigs based on their shot locations, without regard to shot making.
The idea of the 'stretch big' or stretch 4 is actually what first got me thinking about the project. Also the arguments over the value of guys like Tyson Chandler who almost never shoot from more than a few feet away from the basket and the ability of Omer Asik and Dwight Howard to play together.
The cluster analysis creates as many groups as seem to be present in the data, for both Guards and Small Forwards the analyses came up with two in each, one group centered around three point shooters and the other around shots at the rim. For both I named the two groups Slashers and Stretches.
For Bigs I came up with three groups that I am calling At the Rim Bigs, Hybrid Bigs, Stretch Bigs, at least until I think of better labels. This is the first analysis where mid-range shots and long twos were a significant factor in grouping players, because some of the bigs basically don't take any.
Here's how the clusters settled out in shooting location:
| COUNT | AVG Att at the Rim |
AVG Att at 3-9 ft |
AVG Att at Mid Range (10-15) | AVG Att at Long Two(16-23) | AVG Att of Three Pointer | |
| At the Rim Big | 35 | 67.31% | 21.24% | 3.58% | 7.62% | 0.36% |
| Hybrid Big | 90 | 40.31% | 16.47% | 10.94% | 29.88% | 1.96% |
| Stretch Big | 26 | 26.10% | 9.32% | 5.83% | 19.36% | 38.91% |
The 'At the Rim Bigs' on average shot over 67% of their attempts within two feet of the basket, and over 87% within nine feet. Don't bother guarding these guys at the elbow.
The best way to think of the Hybrids are as bigs with a little mid-range and long two game. The defining characteristic of the of the Stretch Big is the three ball.
Below I have some of the more prominent Bigs picked out by sorting for top ePts (effective field goal percentage times shots). I had to add a couple at the end of the list just to get another At the Rim Big onto the list other Dwight Howard.
| PlayerName |
| LaMarcus Aldridge |
| Blake Griffin |
| David Lee |
| Al Jefferson |
| Brook Lopez |
| Al Horford |
| Ryan Anderson |
| Carlos Boozer |
| DeMarcus Cousins |
| Chris Bosh |
| David West |
| Tim Duncan |
| Zach Randolph |
| Dwight Howard |
| Roy Hibbert |
| Kevin Garnett |
Besides the fact that At the Rim Bigs don't, as a rule, seem to shoot much, a couple of things are kind of interesting. Two of the three stretch Bigs are pseudo-bigs, Jeff Green and Derrick Williams, both of whom should see a lot of time at the three this year. Green because of the trade of Paul Pierce, and Williams because of the expected return of Kevin Love.
Also, Dirk just missed the Stretch category. In fact, when the cluster was limited to two groups, he was the only player to switch groups becoming a Stretch with the Hybrid option eliminated.
Outside of volume of scoring the At the Rim Bigs dominate most of the efficiency stats. They score more efficiently, in contrast to the Wings and Guards, where the Stretch groups scored more efficiently. The At the Rim Bigs also rebound more and block more shots. The Stretch Bigs lead in assist percentage and lowest turnover percentage.
| Row Labels | Count | Av TS% | Av eFG% | Av ORB% | Av DRB% | Av AST% | Av BK% | Av TOV% |
| At the Rim Big | 29 | 54.9% | 53.53% | 11.89 | 21.68 | 5.45 | 3.96 | 15.83 |
| Hybrid Big | 78 | 52.8% | 49.12% | 10.07 | 20.37 | 8.47 | 3.04 | 13.23 |
| Stretch Big | 24 | 52.4% | 49.68% | 5.95 | 16.76 | 8.65 | 1.77 | 11.17 |
| Grand Total | 131 | 53.2% | 50.20% | 9.72 | 20.00 | 7.84 | 3.01 | 13.43 |
The advanced one number player metrics for the most part value the At the Rim big guys more than the other Bigs groups. The stretch Bigs are not well liked by the player metrics. As with the guards, I am using Nathan Walker's xRAPM projection and a three year average Wins Produced per 48 from Arturo Galleti, while Win Shares and Daniel Myers' ASPM is a two year average weighted by minutes.
| Row Labels | Count | Avg Proj xRAPM | Avg Wghtd 2 Yr ASPM | Avg WS/48 | Avg WP 3 yrs |
| At the Rim Big | 29 | 0.77 | 0.09 | 0.117 | 0.144 |
| Hybrid Big | 78 | 0.29 | 0.05 | 0.114 | 0.099 |
| Stretch Big | 24 | -1.11 | -1.42 | 0.080 | 0.058 |
| Grand Total | 131 | 0.14 | -0.21 | 0.108 | 0.102 |
Since I combined the Centers and Power Forwards, it was worth it to look the two cardinal positions separately. There are some differences between the positions, especially the relative lack of Stretch Centers, which appears to be a good thing because the stats of the two I found weren't very good. The ratio of At the Rim and Hybrid Bigs is significantly closer.
The At the Rim Centers lead in most efficiency categories, including a gaudy 55.44 average effective field goal percentage.
| Positon | Center |
| Row Labels | Count | Av TS% | Av eFG% | Av ORB% | Av DRB% | Av AST% | Av BLK% | Av TOV% |
| At the Rim Big | 19 | 56.3% | 55.44% | 11.89 | 21.07 | 5.34 | 4.27 | 15.91 |
| Hybrid Big | 36 | 52.5% | 48.98% | 10.52 | 20.85 | 8.40 | 3.46 | 14.29 |
| Stretch Big | 2 | 53.4% | 51.40% | 5.10 | 17.00 | 12.55 | 1.45 | 14.90 |
| Grand Total | 57 | 53.8% | 51.22% | 10.78 | 20.79 | 7.53 | 3.66 | 14.85 |
The metrics all agree, Stretch Centers are a bad idea. Though the fact that one of them is Byron Mullens doesn't help. Nor does it that other, Boris Diaw isn't really a Center.
| Position | Center |
| Row Labels | Count | Avg Proj xRAPM | Avg Wghtd 2 Yr ASPM | Avg WS/48 | Avg WP 3 yrs |
| At the Rim Big | 19 | 0.97 | 0.48 | 0.127 | 0.150 |
| Hybrid Big | 36 | 0.35 | 0.09 | 0.110 | 0.092 |
| Stretch Big | 2 | -1.80 | -2.02 | 0.065 | 0.010 |
| Grand Total | 57 | 0.48 | 0.14 | 0.114 | 0.108 |
The At the Rim power forwards are less dominant in scoring efficiency, but still dominate the boards and blocks.
| Position | Power Forward |
| Row Labels | Count | Av TS% | Av eFG% | Av ORB% | Av DRB% | Av AST% | Av BK% | Av TOV% |
| At the Rim Big | 10 | 52.1% | 49.90% | 11.90 | 22.84 | 5.65 | 3.38 | 15.67 |
| Hybrid Big | 42 | 53.1% | 49.24% | 9.69 | 19.96 | 8.53 | 2.68 | 12.33 |
| Stretch Big | 22 | 52.3% | 49.53% | 6.02 | 16.74 | 8.30 | 1.80 | 10.83 |
| Grand Total | 74 | 52.7% | 49.41% | 8.90 | 19.39 | 8.07 | 2.51 | 12.33 |
The metrics for the Power Fowards are very close between the Hybrid Bigs and At Rim Bigs, the Stretch Bigs still don't fare well:
| Position | Power Forward |
| Values | |||||
| Row Labels | Count | Avg Proj xRAPM | Avg Wghtd 2 Yr ASPM | Avg WS/48 | Avg WP 3 yrs |
| At the Rim Big | 10 | 0.38 | -0.64 | 0.098 | 0.134 |
| Hybrid Big | 42 | 0.24 | 0.01 | 0.117 | 0.106 |
| Stretch Big | 22 | -1.05 | -1.36 | 0.082 | 0.062 |
| Grand Total | 74 | -0.12 | -0.49 | 0.104 | 0.096 |
The next step, eventually, is to look into whether Stretch has an independent effect on offensive efficiency. The basic idea will be to look at line up Stretch against expected efficiency.
Excellent work Andrew! Any time someone attacks positionality with K-means clustering, I'm all for it. (I started work on trying to construct a quality-independent schema/taxonomy of positionality using varying numbers of clusters, but never finished. Check out one of the viz's I was working on here: http://public.tableausoftware.com/views/K-MeansClustering/Dashboard1?:embed=y&:display_count=no )
By the way, my last name is Myers, not Meyers...
Do you have a way to share this post on twitter (and are you on twitter?). I'll probably just link directly anyway, but I thought you might want to add the option if you can.
I look forward to your future posts!
Daniel
Posted by: DSMok1 | 09/10/2013 at 10:00 AM