This is a long article from
http://www.82games.com/comm26.htmVery interesting.
NBA Player Defensive Ratings
Measuring individual defensive player contributions has been arguably the most glaring deficiency of existing NBA statistics. Sure we get tossed a few numbers on blocks and steals, and a beat report will on occasion reference the job a particular player did in shutting down an opposing scorer, but by and large a lot of the defensive kudos that get bandied about are based as much on reputation as on fact.
Ahem, we intend to change that.
Now, maybe not today, probably not even this season, but if all goes well then next year we expect to roll out if not the definitive defensive rating scheme, then the best thing that's been seen to date. Right now what we can publish is a work in progress.
Let's address some of the nuances to what we are trying to achieve here:
One on One Defense: measure how well a player guards his man-to-man assignment.
Help Defense: can the player make defensive stops away from his man.
On/Off Team Defense: what impact does the player have on his team's overall defense when he is on the floor.
We could consider adding in a "clutch" defense metric, perhaps something looking at defense in transition versus half-court, defense in a zone versus a man-to-man assignment, and other additional valuable pieces to the puzzle.
A big question though is what exactly do we mean by defense? Is that just defending the shot? Hardly! Denying a player the ball, forcing turnovers, limiting assists, and even rebounding must be considered.
Yes rebounding. As Dean Oliver has said, offensive rebounding is an offensive skill, defensive rebounding is a defensive skill. Moreover, part of a player's defensive responsibility is to not only grab rebounds, but to prevent his opponent from getting offensive ones.
So, stand back, enter at your own risk...here come the first pass defensive ratings!
(All stats reflect games played through March 3rd of the 2003-2004 season, and generally we require a player to have a minimum of 700 minutes of playing time on the year.)
1) Top NBA One-on-One Defenders
The NBA hasn't bothered to create a full array of individual defensive stats. That's where we come in. We are allocating defensive credits and blame for the events on the floor for all the pertinent areas - shots taken and made, assists, turnovers, free throws, and rebounds.
With regards to rebounds since the expected production is so dependent on the position, we are measuring a player's own defensive rebounds versus the offensive rebounds of his adversary and comparing that to the league norms to come up with an "offensive rebounds allowed" number. A negative "ORA" means the player has restricted his opponent to getting less offensive rebounds than would be expected -- a good thing!
Now the key problem with these ratings it can be argued is that they don't measure the caliber of the opponent who is being guarded. Indeed some of the guys with strong defensive reputations end up guarding the opposition's strongest scorer on a consistent basis which means that their personal rating is harmed while a lesser defender teammate may be reaping the benefits. Likewise, defense is never solely an individual endeavor, since having Yao Ming behind you can make a big difference in the way you play a man on the perimeter. Finally, a player's defensive prowess is being gauged as the defense at that position. Ron Artest may be a fabulous defender, but we would hardly expect him to guard Shaq, and neither would a smart coach ask Shaq to guard Steve Francis at the three-point line.
Nevertheless, even with acknowledged flaws, and without delving into the depths of how these ratings are calculated, here are the current leaders in man defense.
Notes: These stats measure the performance of the opponent the player is adjudged to be guarding. eFG = "effective field goal percentage" adjusted for 3pt shots made, ORA = offensive rebounds allowed compared to league averages.
Rk Player Team Rtg FGM FGA eFG FTM FTA Ast T/O OReb ORA
1 Duncan SAS 67.4 261 727 .369 115 158 98 99 164 -54
2 Garnett MIN 68.3 335 891 .389 194 243 140 151 163 -126
3 Camby DEN 69.6 231 581 .403 116 171 91 118 123 -46
4 Dalembert PHI 71.0 171 492 .350 105 185 59 83 158 38
5 O'Neal LAL 71.6 192 497 .389 69 105 67 51 119 -23
6 Wallace DET 72.5 333 797 .423 141 202 97 170 213 -26
7 Cato HOU 73.1 217 589 .380 125 183 91 86 108 -16
8 Haywood WAS 73.6 116 315 .370 58 84 45 51 75 18
9 Martin NJN 74.3 274 671 .423 146 191 112 133 115 -59
10 Gadzuric MIL 74.5 118 320 .373 90 121 43 65 81 5
11 Nesterovic SAS 74.9 210 538 .393 104 171 85 95 129 12
12 O'Neal IND 75.7 307 779 .399 155 211 113 97 159 -30
13 Kirilenko UTA 76.0 280 740 .404 170 218 127 166 126 3
14 Ginobili SAS 76.2 238 578 .455 113 149 124 157 44 -41
15 Artest IND 76.7 242 580 .454 98 135 150 158 72 -21
16 Ratliff ATL 77.6 214 585 .369 100 152 80 68 166 48
17 Campbell DET 77.9 82 211 .393 51 73 42 34 54 0
18 Prince DET 77.9 306 774 .425 107 139 142 108 78 -29
19 Tinsley IND 78.0 109 295 .402 61 75 155 79 22 -9
20 Mutombo NYK 78.0 206 536 .387 102 137 77 54 116 -1
21 Ming HOU 78.1 245 622 .397 127 199 70 60 160 -3
22 Dampier GSW 78.2 266 632 .423 95 158 97 72 169 -13
23 Thomas WAS 78.8 167 425 .404 84 112 75 66 111 7
24 Andersen DEN 79.3 150 365 .419 78 105 42 68 88 8
25 Kidd NJN 79.4 290 703 .467 115 142 314 161 28 -103
The first thing to notice is that the list is dominated by big men. This is in some ways acceptable since it is much tougher to score over a big man then a small man, but may reflect a bias in the big guys getting too much credit for the blocks they make on the instances where a player they were initially not guarding has the audacity to venture into the paint.
At a glance though the ratings seem to pass the so called "laugh test" as players with huge defensive reputations like Duncan, Ben Wallace, Artest, Kirilenko, Prince and Ming wind up in the top echelon. So far, so good. Ah, but as we alluded to at the start, we think putting an emphasis on a player's influence on the overall team defense is of vital consideration as well.
2) On Court Defensive Impact
A simple number is the team defense in terms of points allowed per 100 possessions while a player is on the floor.
Rank Player Team Pts/Poss
1 Foster IND 94.3
2 Horry SAS 94.3
3 Tinsley IND 94.4
4 Collins NJN 94.4
5 Nesterovic SAS 95.4
6 Turkoglu SAS 95.4
7 Bowen SAS 95.6
8 Duncan SAS 96.1
9 Martin NJN 96.3
10 Kidd NJN 96.4
The weakness of this measure is immediately evident -- it's too much a reflection of the team, and not specific enough to the player. All ten spots are grabbed by just three teams, and looking at the top 20 instead doesn't expand the view much.
Defense is also influenced by the offense -- a team that looks to run, or aggressively goes after offensive rebounds can weaken the defense at the other end.
3) On Court versus Off Court Team Defense
In light of the problems with the raw look then, a better look would be based on the performance of the team defensively (points allowed per 100 possessions) when the player is on court versus when he is on the bench.
Rk Player Team ON OFF Net
1 Peeler SAC 99.1 109.8 -10.7
2 Outlaw MEM 97.9 107.7 -9.8
3 Garnett MIN 100.2 109.4 -9.2
4 James SEA 103.9 112.4 -8.6
5 Foster IND 94.3 102.3 -8.0
6 Nene DEN 101.6 109.3 -7.7
7 Watson MEM 99.8 107.3 -7.5
8 Collins NJN 94.4 101.8 -7.4
9 Ratliff ATL 102.7 109.9 -7.2
10 Davis NOH 102.9 110.1 -7.2
11 Lopez UTA 102.2 109.1 -6.9
12 Cato HOU 97.2 104.0 -6.8
13 Abdur-Rahim ATL 103.6 110.5 -6.8
14 Simmons LAC 105.6 112.4 -6.8
15 Jackson HOU 98.9 105.6 -6.7
16 Anderson POR 104.0 110.6 -6.6
17 Malone LAL 99.5 105.8 -6.3
18 Hassell MIN 99.2 105.4 -6.2
19 Tinsley IND 94.4 100.4 -6.0
20 Curry TOR 97.6 103.3 -5.7
Peeler was used as a defensive stopped in Minnesota last season, and is reacquainted with the role this year in Sacto. Bo Outlaw is another unsung hero who can be a force on the defensive end (Phoenix's prospects for this season went downhill the moment he was traded).
We also catch a number of players with good defensive work ethics in the likes of Foster, Nene, Ratliff, Hassell and Curry.
A number of the players making the top twenty could be considered under-rated, but not all of them have strong overall effects for the team since their offensive shortcomings in some cases seriously detract from their defensive strengths.
4) Forcing Turnovers
On defense it might be said that the sequence of events a defender can bring about from best scenario to worst runs like this: turnover, missed shot, pass, free throws, made field goal. With a turnover, the opponent has been completely stopped, and in the cases of steals the ensuing possession has a higher than expected value for the team making the theft. Consequently there is emphasis around the league on finding players who can force turnovers.
Rk Player Team T/O% Ast T/O
1 Foster IND 22.5% 59 111
2 Blount CHI 21.4% 37 63
3 Claxton GSW 21.3% 252 138
4 Barbosa PHO 20.9% 148 90
5 Armstrong NOH 19.8% 279 171
6 Artest IND 19.5% 150 158
7 DeClercq ORL 19.2% 36 59
8 James BOS 19.1% 327 139
9 Madsen MIN 19.1% 49 58
10 Williams CHI 18.9% 104 98
11 Ginobili SAS 18.8% 124 157
12 Nene DEN 18.8% 125 147
13 Posey MEM 18.5% 150 158
14 Tinsley IND 18.2% 155 79
15 Collins UTA 18.1% 55 76
Several different stats could be used to evaluate which players cause turnovers for the opposition, but we elected to go with a percentage of possesions that the defender brought about the "big no-no" from his adversary.
Jeff Foster is surrounded by some notable defensive talent in Indiana and clearly makes the most of his chances to be a factor defensively himself. The leaders are a diverse group as it turns out, with big men (Madsen, Blount, DeClerq), small guards (Claxton, Barbosa, Armstrong), and swingmen troublemakers (Artest, Ginobili, Posey).
5) Overall Defensive Player Leaders
We've touched on a number of areas that are part of a good defensive player's makeup, but now comes the hard part -- constructing a comprehensive rating that attempts to account for the different components in a reasonable fashion.
Rank Player Team 1on1 Tm ON Tm OFF On/Off Rating
1 Garnett MIN 68.3 100.2 109.4 -9.2 75.9
2 Duncan SAS 67.4 96.1 96.6 -0.5 76.8
3 Cato HOU 73.1 97.2 104.0 -6.8 78.9
4 Dalembert PHI 71.0 100.5 106.0 -5.5 79.0
5 Martin NJN 74.3 96.3 100.7 -4.3 80.2
6 Wallace DET 72.5 99.0 101.5 -2.5 80.5
7 Camby DEN 69.6 103.8 105.2 -1.4 80.6
8 Nesterovic SAS 74.9 95.4 97.5 -2.1 81.0
9 O'Neal IND 75.7 97.3 102.0 -4.7 81.3
10 Tinsley IND 78.0 94.4 100.4 -6.0 81.5
11 O'Neal LAL 71.6 103.2 105.1 -1.9 81.5
12 Artest IND 76.7 97.3 101.3 -4.1 82.2
13 Haywood WAS 73.6 103.5 106.4 -2.9 82.6
14 Kidd NJN 79.4 96.4 102.0 -5.6 83.2
15 Ginobili SAS 76.2 96.6 95.7 +0.9 83.3
16 Peeler SAC 80.9 99.1 109.8 -10.7 83.4
17 Ratliff ATL 77.6 102.7 109.9 -7.2 83.6
18 Gadzuric MIL 74.5 104.4 106.7 -2.3 83.7
19 Foster IND 82.7 94.3 102.3 -8.0 83.9
20 Prince DET 77.9 98.8 101.3 -2.5 84.0
21 Collins NJN 83.8 94.4 101.8 -7.4 84.9
22 Kirilenko UTA 76.0 105.5 107.9 -2.4 85.0
23 Ming HOU 78.1 100.4 100.2 +0.2 85.6
24 Campbell DET 77.9 100.2 99.3 +0.9 85.6
25 Turkoglu SAS 81.7 95.4 97.1 -1.7 85.7
Well, let the debates begin. Ben Wallace is arguably the player who would win a fan poll of strongest defensive force, but he checks in at #6 overall. Instead we are back to the ongoing MVP discussion of Duncan versus Garnett, and Kevin Garnett wins the photo finish this time, albeit a few tweaks to our algorithms can easily flip the order.
Kelvin Cato's prominence is a surprise, but playing next to the 7'5" Ming clearly has its benefits. Jamaal Tinsley claims top placement for a backcourt player.
Since despite our best efforts there does appear to be a noticable favoritism in the rankings towards shotblockers, another look, this time breaking it out by position (and yes classifying certain players is difficult and arbitrary) might be in order:
Point Guards Rank Player Team 1on1 Tm ON Tm OFF On/Off Rating
1 Tinsley IND 78.0 94.4 100.4 -6.0 81.5
2 Kidd NJN 79.4 96.4 102.0 -5.6 83.2
3 Watson MEM 83.3 99.8 107.3 -7.5 86.3
4 Davis NOH 84.8 102.9 110.1 -7.2 88.4
5 Ward NYK 83.0 102.5 104.9 -2.4 88.7
6 Lopez UTA 87.0 102.2 109.1 -6.9 89.7
7 James BOS 82.6 105.4 105.0 +0.5 90.4
8 Fisher LAL 85.7 102.8 105.1 -2.3 90.6
9 Francis HOU 87.8 99.8 102.5 -2.6 90.9
10 Hinrich CHI 87.0 104.0 109.1 -5.2 90.9
Tinsley and Kidd stand apart by our ratings, and since they are 1-2 in individual defense and in the "Team On" defense that feels fairly convincing. Baron Davis is also justifiably regarded highly for his opponent-stopping efforts.
Shooting Guards Rank Player Team 1on1 Tm ON Tm OFF On/Off Rating
1 Ginobili SAS 76.2 96.6 95.7 +0.9 83.3
2 Peeler SAC 80.9 99.1 109.8 -10.7 83.4
3 Jones IND 81.2 100.1 97.6 +2.5 88.3
4 Hardaway NYK 81.6 103.7 104.4 -0.6 88.7
5 Miller IND 87.2 97.3 100.3 -3.0 89.6
6 Mobley HOU 84.1 100.4 99.9 +0.5 89.7
7 Kittles NJN 85.7 97.8 97.5 +0.3 89.8
8 Posey MEM 83.9 103.6 105.1 -1.4 90.0
9 Hassell MIN 88.7 99.2 105.4 -6.2 90.1
10 Wells MEM 86.6 101.5 105.8 -4.2 90.2
The Shooting Guards as a class have poorer defensive ratings, which is as much a testament to the overall offensive skills of the position as a criticism of the defensive efforts. The "Two Guards" are often the best pure shooters on the court, but have the quickness and explosiveness as well, combined with some decent offensive rebounding if you're not paying attention -- all in all a tough package to defend against. One thought also goes that the shooting guards expend so much energy on offense (frequently the highest possession users on a team) that they sometimes use the defensive end to catch up.
Small Forwards Rank Player Team 1on1 Tm ON Tm OFF On/Off Rating
1 Artest IND 76.7 97.3 101.3 -4.1 82.2
2 Prince DET 77.9 98.8 101.3 -2.5 84.0
3 Turkoglu SAS 81.7 95.4 97.1 -1.7 85.7
4 Jackson HOU 82.5 98.9 105.6 -6.7 85.7
5 Horry SAS 83.6 94.3 97.2 -3.0 86.1
6 George LAL 81.4 102.2 106.3 -4.0 87.0
7 Peterson TOR 82.5 100.1 103.0 -2.9 87.4
8 Jefferson NJN 84.0 97.4 99.2 -1.8 87.9
9 Miles CLE 82.3 104.2 106.3 -2.1 88.9
10 McKie PHI 83.9 102.2 104.2 -2.0 89.4
We're big fans of Ron Artest's game, and while challenged by Tayshaun Prince who showed some defensive magic against the Magic in last year's playoffs, Artest is still the best at his most common position. The Spurs meanwhile have three of the top Small Forwards (Bowen is just off the table we show here), which perhaps suggests the system is to be praised as much as the individual players.
Power Forwards Rank Player Team 1on1 Tm ON Tm OFF On/Off Rating
1 Garnett MIN 68.3 100.2 109.4 -9.2 75.9
2 Duncan SAS 67.4 96.1 96.6 -0.5 76.8
3 Cato HOU 73.1 97.2 104.0 -6.8 78.9
4 Martin NJN 74.3 96.3 100.7 -4.3 80.2
5 O'Neal IND 75.7 97.3 102.0 -4.7 81.3
6 Kirilenko UTA 76.0 105.5 107.9 -2.4 85.0
7 Andersen DEN 79.3 103.2 105.0 -1.7 86.7
8 Outlaw MEM 86.4 97.9 107.7 -9.8 87.0
9 Okur DET 84.0 97.4 101.1 -3.7 87.2
10 Rose SAS 80.1 99.5 95.0 +4.6 88.1
Duncan's individual defense is better, and the team performance is clearly the best in the league, however Garnett's On Court/Off Court influence is so strong that he winds up in front. Kenyon Martin may not be banging up against the best of the West on a nightly basis, but he too has shown some formidable defensive props.
Centers Rank Player Team 1on1 Tm ON Tm OFF On/Off Rating
1 Dalembert PHI 71.0 100.5 106.0 -5.5 79.0
2 Wallace DET 72.5 99.0 101.5 -2.5 80.5
3 Camby DEN 69.6 103.8 105.2 -1.4 80.6
4 Nesterovic SAS 74.9 95.4 97.5 -2.1 81.0
5 O'Neal LAL 71.6 103.2 105.1 -1.9 81.5
6 Haywood WAS 73.6 103.5 106.4 -2.9 82.6
7 Ratliff ATL 77.6 102.7 109.9 -7.2 83.6
8 Gadzuric MIL 74.5 104.4 106.7 -2.3 83.7
9 Foster IND 82.7 94.3 102.3 -8.0 83.9
10 Collins NJN 83.8 94.4 101.8 -7.4 84.9
Lastly we come to the big Kahunas, the men in the middle, the last line of defense. Samuel Dalembert is not exactly a household name, but after missing the entire 2002-03 season, he's come back as a polished player, at least on the defensive end. Opposing centers have really struggled to put points on the board against him, and wayward players of other positions that venture into his domain have seen more than a few shots swatted in the opposite direction.
Of course, that's not likely to win over any of the legion of Ben Wallace fans, whose jaws are dropping when they see their guy comes in at #2. Then you have the Theo Ratliff contingent -- and big Theo has posted a 76.4 overall defensive rating in his short stint in Portland thus far, so if he can keep that up he will be a dark horse for the year end title.
