HANG TIME NEW JERSEY — Points, rebounds and assists are nice, but plus-minus is the most important stat in basketball.
Teams win games by outscoring their opponent, and plus-minus reflects how much a team has done that in a player’s minutes on the floor. If a player isn’t scoring, he can help his teammates score and also prevent the opponent from doing so.
But in basketball, with nine other guys on the floor affecting what each player does, plus-minus always needs context, and lots of it. Who is a guy playing his minutes with? Who is he not playing his minutes with?
Furthermore, sample size is important. Single-game plus-minus can help tell a story about key sequences or the impact of a player or two on a particular night. But if you really want to get a good idea of how a team performs when a player or group of players is on the floor, you’ve got to look at a large chunk of games.
At this point in the season, we can get a pretty good idea of where teams are strong and weak. Through Thursday, 224 players have logged at least 500 minutes for one team this season.
On Wednesday, we looked at the players with the biggest on-off court differential in regard to their team’s offensive efficiency. Today, we look at the defensive end of the floor.
Measuring the difference in a team’s offensive efficiency (points scored per 100 possessions) when a player is on the floor vs. when he’s off the floor, here are the league’s five biggest difference makers, as well as a pair at the bottom of the list.
For all of them, the discrepancy between their team’s defensive numbers with them on and off the floor is as much about the guys replacing them as it is about what they’re doing themselves.
1. Kevin Garnett, Celtics
Because the Celtics use a unique substitution pattern with KG, you can get a pretty clear idea of the impact he makes. No other Celtics regular has played more 63 percent of his minutes with Garnett.
You probably figured Garnett would be at or near the top of this list, but 14.4 points per 100 possessions? That’s an amazing number, and it’s an indictment on Brandon Bass (382 minutes with Garnett off the floor), Jared Sullinger (331) and Chris Wilcox (297) … and Paul Pierce (391) and Rajon Rondo (432).
It’s also an endorsement of both former Celtics center Greg Stiemsma and guard Avery Bradley, because the Celtics’ defense only fell off 0.5 points per 100 possessions when Garnett stepped off the floor last season.
Bradley’s return (he made his 2012-13 debut on Wednesday) offers some hope, but interior defense will continue to be an issue whenever Garnett rests.
2. Lamar Odom, Clippers
Odom has been working himself back into shape over the first two months of the season and has looked very rusty offensively. But he’s part of a Clippers’ bench that has been more effective than their starters.
The L.A. starting lineup (with Willie Green at shooting guard) has been better offensively, but has outscored its opponents by just 4.4 points per 100 possessions in 429 minutes. The second unit (Eric Bledsoe, Jamal Crawford, Matt Barnes, Odom and Ronny Turiaf) has outscored its opponents by an amazing 15.6 points per 100 possessions in 230 minutes, playing far better defense.
This is a stark contrast from last season, when Blake Griffin had the highest overall on-off court differential in the league (and Chris Paul had the fifth-highest). The Clips were outscored by 11.6 points when Griffin was off the floor last year, but they’re a +10.6 this season.
Odom had a pretty good impact on the Lakers’ defensive numbers before his career went off track in Dallas. Over his last three seasons in L.A., the Lakers allowed just 99.8 points per 100 possessions with Odom on the floor and 104.2 with him on the bench.
3. Jared Dudley, Suns
Dudley’s on-off court differential has a lot to do with the Suns’ deadly (in a bad way) defensive trio of Michael Beasley, Shannon Brown and Markieff Morris. Phoenix has allowed an absolutely atrocious 126 points per 100 possessions in 223 minutes with those three guys on the floor together, and Dudley has been on the bench for all 223 of those minutes.
Alvin Gentry wisely stopped using that trio for almost a month, but then went back to it on Wednesday against the Sixers. The Suns were outscored 17-6 in less than seven minutes with them on the floor.
Dudley himself is a solid defender, and he has played most of his minutes with other solid defenders like Goran Dragic, Luis Scola and Marcin Gortat. Dudley and P.J. Tucker have made a pretty good defensive wing combo, too.
4. Kemba Walker, Bobcats
Let’s get this straight: 105.0 points allowed per 100 possessions is bad defense, and 116.1 points allowed per 100 possessions is phenomenally bad defense.
Still, Walker is a decent defender — much better than Ben Gordon, at least. And it has helped that Michael Kidd-Gilchrist, Brendan Haywood and Jeff Taylor — three good defenders — have all played at least 73 percent of their minutes with Walker. The Bobcats have allowed just 90.2 points per 100 possessions in 198 minutes with those four all on the floor together.
But they rank dead last in the league in defensive efficiency (108.0) because they’ve played 1,306 minutes with other combinations.
5. Larry Sanders, Bucks
Sanders is a defensive force and when he’s teamed with Luc Mbah a Moute or Ekpe Udoh, the Bucks shine defensively. But offense is another story. And Sanders is at the complete opposite end of the list when it comes to offensive on-off court differential. The Bucks score 10.3 points per 100 possessions more when Sanders sits on the bench than when he plays.
220. Carlos Boozer, Bulls
The Bulls aren’t a bad defensive team with Boozer on the floor. They still allow less than the league average points per 100 possessions (102.3). But they’re just much, much better defensively with Taj Gibson at power forward … as long as Boozer isn’t the center. Chicago has allowed 114 points per 100 possessions with Gibson and Boozer on the floor together.
223. Al Jefferson, Jazz
If there’s a high-scoring big man who’s worse defensively than Boozer, it’s Al Jefferson. And if the Jazz want to be a good defensive team going forward, Jefferson is the impending free agent that they trade or let walk this summer.
The problem is that the Jazz have been pretty bad offensively, scoring less than a point per possession, with young bigs Derrick Favors and Enes Kanter on the floor together.