Attention Orlando Magic, C.J. McCollum’s brother: Higher defensive rating is worse

C.J. McCollum in Trail Blazers-Magic
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The Magic have allowed 112.7 points per 100 possessions this season – the NBA’s eighth-worst defensive rating. The Trail Blazers have fared even worse with C.J. McCollum on the floor, allowing 113.5 points per 100 possessions.

These are not statistics to brag about.

Yet…

Orlando implicitly bragged about its high defensive rating in a since-deleted trivia tweet.

Rob Perez of The Action Network:

And Errick McCollum defended his brother’s defense by highlighting the Portland guard’s higher-than-average defensive rating:

Unlike the Magic, Errick McCollum didn’t delete his tweet. Instead, he shifted his argument:

These are good points! Defensive rating is a team stat, though it’s often ascribed to players. That’s why I prefer to say, “The Trail Blazers have a 113.5 defensive rating with McCollum on the floor” rather than “McCollum has a 113.5 defensive rating.”

It indicates something positive about McCollum’s defense that the Trail Blazers have allowed fewer points per possession with him on the floor than without him.

But that isn’t the full story, either. McCollum has played more with Portland’s most versatile and arguably best defender, Robert Covington, than with anyone else. The other player in the discussion for the Trail Blazers’ best defender, Jusuf Nurkic, has played a high majority of his minutes with McCollum.

Some advanced defensive statistics attempt to incorporate those factors into a single metric. McCollum’s…

With all three measures, average is 0. But the tricky part: In all three, higher is better. So, McCollum rates slightly below average by defensive estimated plus-minus, well above average by defensive real-plus minus and slightly above average by defensive RAPTOR.

This can get confusing.

But defensive rating is a fairly simple statistic.* It’s just points allowed per 100 possessions. Once you know that, higher is obviously worse.

So, when someone makes the (understandable) mistake of using a higher defensive rating to show “better” defense, yeah, it can still be funny.

*Basketball-Reference previously published a more complicated individual “defensive rating.” That unreliable statistic has fallen by the wayside. Higher was worse in that metric, too.

By the way, the answer to the Magic’s trivia question: 1989-90, Orlando’s inaugural season (114.3 defensive rating). The Magic went 18-64 that year, which should have been a clue a high defensive rating isn’t good.

That’s really the best way to keep this straight: Look for players like Rudy Gobert and teams like the Lakers. Whichever side of the spectrum they’re on – whether it’s a positive or negative number – is probably the good side.