ezPM Compared with RAPM: Part II (Offense and Defense)


In a previous post, I showed the results for regressions of ezPM against 1-yr and 3-yr RAPM (regularized adjusted +/-). Now, let’s take a look at how the offensive and defensive components of ezPM correlate with their RAPM counterparts. If you are familiar with ezPM, then you know I typically calculate three separate components: O100, D100, and REB100. To enable comparison with RAPM data, I folded the REB100 into O100 and D100, to give total offense and defense components (i.e. that include offensive and defensive rebounding, respectively). Just as a quick refresher, I re-ran the regression for the overall metric comparison, this time weighting by possession number, and focusing only on the 3-yr data set:


RAPM as a function of EZPM (3-YR).

Call:lm(formula = RAPM ~ EZPM100, data = tot, weights = POSS) Residuals:    Min      1Q  Median      3Q     Max  -528.06  -84.51   -7.21   64.96  613.87  Coefficients:             Estimate Std. Error t value Pr(>|t|)     (Intercept)  0.81273    0.09070    8.96   <2e-16 *** EZPM100      0.60519    0.03686   16.42   <2e-16 *** ---Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1  Residual standard error: 142.3 on 381 degrees of freedom Multiple R-squared: 0.4144, Adjusted R-squared: 0.4129  F-statistic: 269.6 on 1 and 381 DF,  p-value: < 2.2e-16

You can see that there is a slight increase in R^2 to 0.41 from 0.37 previously. Now, let’s look at the regression results for the offense:


RAPM vs. EZPM (3-YR Offense)

lm(formula = OFF_RAPM ~ O100, data = off, weights = POSS) Residuals:    Min      1Q  Median      3Q     Max  -399.88  -84.15  -19.91   45.38  564.10  Coefficients:            Estimate Std. Error t value Pr(>|t|)     (Intercept) -0.23537    0.09328  -2.523   0.0120 *   O100         0.57146    0.04266  13.395   <2e-16 *** ---Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1  Residual standard error: 117.6 on 381 degrees of freedom Multiple R-squared: 0.3201, Adjusted R-squared: 0.3184  F-statistic: 179.4 on 1 and 381 DF,  p-value: < 2.2e-16

The correlation between the individual offensive components of ezPM and RAPM is significant (p<2.2e-16) and R^2=0.32. As I did last time, I want to give a table showing the best and worst players according to an average of the two metrics (note Warriors guard Charlie Bell shows up on the Bottom 20):

Top 20 Offensive Players (> 5000 Possessions)

RANK NAME OFF_RAPM OFF_ezPM AVG
1 LeBron James 6.90 7.19 7.05
2 Steve Nash 7.80 5.56 6.68
3 Dwyane Wade 6.30 6.05 6.18
4 Chris Paul 5.10 7.07 6.09
5 Dwight Howard 3.60 6.37 4.99
6 Deron Williams 4.50 4.60 4.55
7 Chauncey Billups 3.90 4.72 4.31
8 Pau Gasol 2.90 5.67 4.29
9 Dirk Nowitzki 5.10 3.16 4.13
10 Manu Ginobili 4.20 3.74 3.97
11 Kobe Bryant 4.30 3.60 3.95
12 Brandon Roy 3.60 3.88 3.74
13 Chris Bosh 3.10 4.05 3.58
14 Kevin Martin 3.50 2.84 3.17
15 Joe Johnson 3.90 2.38 3.14
16 Nene Hilario 2.00 4.25 3.13
17 Amare Stoudemire 2.40 3.59 3.00
18 Ty Lawson 2.10 3.85 2.98
19 Carmelo Anthony 3.30 2.58 2.94
20 Kevin Love 0.90 4.94 2.92

Bottom 20 Offensive Players (> 5000 Possessions)

RANK NAME OFF_RAPM OFF_ezPM AVG
237 Donte Greene -1.10 -2.76 -1.93
236 Chris Kaman -2.80 -0.83 -1.82
235 Rasual Butler -2.10 -1.41 -1.76
234 Yi Jianlian -1.60 -1.87 -1.74
233 J.J. Hickson -3.30 -0.07 -1.69
232 Jonny Flynn -0.60 -2.55 -1.58
231 Corey Brewer -0.80 -2.21 -1.51
230 Brandon Rush -1.70 -1.31 -1.51
229 Dahntay Jones -2.90 0.08 -1.41
228 Darko Milicic -2.10 -0.45 -1.28
227 Jason Kapono -0.80 -1.74 -1.27
226 Tyrus Thomas -2.30 0.14 -1.08
225 Andray Blatche -1.70 -0.41 -1.06
224 Spencer Hawes -0.90 -1.08 -0.99
223 Joel Anthony -3.30 1.34 -0.98
222 Charlie Bell -0.90 -0.98 -0.94
221 Rafer Alston -0.80 -0.98 -0.89
220 Trevor Ariza -1.40 -0.32 -0.86
219 Tyreke Evans -2.10 0.46 -0.82
218 Kurt Thomas -1.80 0.18 -0.81

Here are the results for the defense:


ezPM vs. RAPM (3-YR Defense)

lm(formula = DEF_RAPM ~ D100, data = def, weights = POSS) Residuals:    Min      1Q  Median      3Q     Max  -392.80  -51.15    6.09   61.18  372.19  Coefficients:            Estimate Std. Error t value Pr(>|t|)     (Intercept)  1.02475    0.08468   12.10   <2e-16 *** D100         0.54199    0.04460   12.15   <2e-16 *** ---Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1  Residual standard error: 102.1 on 381 degrees of freedom Multiple R-squared: 0.2793, Adjusted R-squared: 0.2774  F-statistic: 147.7 on 1 and 381 DF,  p-value: < 2.2e-16

Once again the results are statistically significant (p<2.2e-16) and, perhaps, somewhat surprisingly, the R^2 value of 0.28 is only slightly lower than for the offense. This tells me that we are capturing quite a bit of the same defensive contributions as RAPM. To wrap it up, here are tables for the top and bottom players averaged by the two metrics (unfortunately, you will notice that $15M-man David Lee shows up on the less preferred of the two lists):

Top 20 Defensive Players (> 5000 possessions)

RANK NAME DEF_RAPM DEF_ezPM AVG
1 Kevin Garnett 6.2 2.49 4.35
2 Dwight Howard 3.0 3.87 3.44
3 LeBron James 3.8 2.6 3.20
4 Andrew Bogut 4.1 1.88 2.99
5 Tim Duncan 3.5 2.08 2.79
6 Josh Smith 3.8 1.48 2.64
7 Gerald Wallace 3.0 2.19 2.60
8 Marcus Camby 3.0 2.03 2.52
9 Andrei Kirilenko 2.6 1.88 2.24
10 Ron Artest 3.2 0.88 2.04
11 Ben Wallace 2.5 1.37 1.94
12 Lamar Odom 3.4 0.38 1.89
13 Thabo Sefolosha 2.5 0.98 1.74
14 Kurt Thomas 2.6 0.85 1.73
15 Luol Deng 2.8 0.61 1.71
16 Trevor Ariza 2.1 1.29 1.70
17 Manu Ginobili 1.6 1.53 1.57
18 Tyrus Thomas 1.6 1.43 1.52
19 Anderson Varejao 2.1 0.81 1.46
20 James Harden 2.0 0.9 1.45

Bottom 20 Defensive Players (> 5000 Possessions)

RANK NAME DEF_RAPM D100 AVG
237 Andrea Bargnani -3.1 -3.07 -3.09
236 Aaron Brooks -1.8 -3.86 -2.83
235 Charlie Villanueva -2.8 -2.75 -2.78
234 Kevin Martin -3.8 -1.72 -2.76
233 Will Bynum -1.8 -3.47 -2.64
232 Jason Kapono -1.1 -3.98 -2.54
231 D.J. Augustin -0.8 -4.15 -2.48
230 JaVale McGee -1.7 -3.17 -2.44
229 Jason Maxiell -1.2 -3.61 -2.41
228 Spencer Hawes -1.6 -3.01 -2.31
227 Goran Dragic -1.1 -3.5 -2.30
226 Jose Calderon -1.7 -2.67 -2.19
225 Jeff Green -2.2 -2.14 -2.17
223 Antoine Wright -0.9 -3.43 -2.17
224 Jonny Flynn -1.6 -2.73 -2.17
222 J.J. Hickson -2.6 -1.63 -2.12
221 David Lee -1.9 -2.31 -2.11
220 Devin Harris -1.1 -3.03 -2.07
219 Ben Gordon -2.1 -1.99 -2.05
218 Maurice Evans -1.5 -2.52 -2.01

 

4 responses to “ezPM Compared with RAPM: Part II (Offense and Defense)

  1. Very few guys under 25 yrs on either top 20 while more than half of the bottom 20s are taken by them.

    I thought Hickson had some promise but the advanced metrics of EZPM and Adjusted +/- both rate his performance as poor. So far the numbers suggest he is better at C but they play him more at PF.

  2. Hi
    Your league wide analyses are interesting but I’d like you to return to being the “Warriors Centric” blog. The hope is to find some keys to why they are not more successful. One question in my mind is should they or should they not play Jeremy Lin more.

    Thanks

    • Norm, they should probably play Lin more, so he can develop. Then again, they should have let Brandan Wright do the same, so I’m not sure developing talent is their goal right now (unfortunately).

      You want to know why the team is not winning more? I think the number one factor is that the talent is simply not there. Curry, Ellis, and D. Wright could probably all be pieces of winning teams. I’m not sure that the same could be said for Lee and Biedrins at this point. My opinion is that Lacob needs to seriously consider breaking this team up in the off-season and re-building from the ground up, perhaps, keeping only Curry, Williams, Udoh, and D. Wright who are each cheap and talented. Ellis and Biedrins should be traded for first round draft picks, if possible, or expiring contracts and multiple second round picks, at the very least. We’re stuck with Lee, because his contract is probably untradeable. I know it sounds gloomy, but it’s better to be realistic than to pretend there is something here that can legitimately contend for a title (or even a playoff spot).

  3. Pingback: PSAMS Regressed on ORAPM: A New Variant of Statistical +/- for Offense | The City

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