Patrick and I use a lot of advanced stats on this site, and I think there’s a good reason for it. When used properly, advanced stats can often provide a better assessment of what’s happening on the court than traditional stats.
But we don’t always do the best job of explaining advanced stats to those who don’t otherwise understand them. I’d like to do that more often, and today’s a great excuse to talk about team offensive and defensive rating (sometimes called offensive and defensive efficiency).
Offensive rating is designed to replace team points per game, and defensive rating replaces team points allowed per game.
These advanced stats account for possessions alternating no matter what. When a team scores with 21 seconds left on the shot clock, its opponent gets the ball. When a team scores with three seconds left on the shot clock, its opponent gets the ball.
The team that scores quickly will obviously score more points, but is that really beneficial if it’s just giving its opponent more opportunities to score?
On the flip side, a team that takes more time to score will score fewer points, but it also limits its opponents opportunities to score.
That’s why points per game and point per game allowed are inefficient. Those stats depend too much on a team’s pace.
A fast team might have a poor offense and great defense, but it will still rank well in points per game and poorly in points per game allowed. A slow team might have a great offense and poor defense, but it will still rank poorly in points per game and well in points per game allowed.
Offensive and defensive rating fix those problems because they’re based on points per 100 possessions, not points per game.
If a team scores 12 points in 10 possessions, its offensive rating would be 120. Likewise, if a team allows 12 points 10 possessions, its defensive rating would be 120.
It’s a pretty simple stat that ranks offenses and defenses without the noise of pace.
What this has to do with the Pistons
The Pistons are the league’s 28th-slowest team, averaging just 89.5 possessions per 48 minutes. That means their points per game and points per game allowed will be lower than the quality of their play represents.
Assuming those traditional numbers accurately characterizes the team’s offense and defense leads to misguided articles like this: Pistons have to find ways to score more points, by Perry A. Farrell of the Detroit Free Press.
The Pistons rank 24th in the league in points per game (96.6) and 19th in points allowed per game (101.1), so on face value, Farrell’s decision to focus on offensive shortcomings makes sense.
But a more accurate picture shows the Pistons’ offense is ahead of their defense.
Detroit’s offense rating (105.4) ranks 20th, and its defensive rating (110.2) ranks 25th.
The more you know…
As people who spend a lot of time writing about basketball and reading about basketball, Patrick and I can easily get caught up in advanced stats and assume everyone else is on board. If you ever a have a question about a stat we use, ask in the comments, and we’d be happy to explain.
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