Diving into Some On-Off Numbers: Westbrook and The Greek

Published on 22-Dec-2016 by Colin Chiles
Basketball - NBA / NBA Daily Opinion

Are the numbers accurate?

Time to do some crunching.

On-off numbers are stats that were inspired by hockey's plus-minus figures.

And yes, there are lies, damned lies, and statistics.

So these can be a little tricky, and they never tell the whole story, but they do have a story to tell.

I’m going to be using the Basketball-Reference on-off numbers, which at the team level essentially tells us how many points per 100 possessions a player is scoring.

If you’re curious to see a more detailed breakdown, click on a player’s name, and it’ll link you to the full stats.

In this first edition, let's delve into Russell Westbrook's numbers.

OKC with Westbrook on the floor   OKC with Westbrook off the floor
  Offensive rating ... 109.9     Offensive rating ... 96.4
  Opponents offensive rating ... 104.2     Opponents offensive rating ... 109.9

We can take both pairs of numbers and create a difference, which is found in the last section of the Basketball-Reference page.

So, crunching some really tough addition and subtraction -- 109.9-104.2=5.7 and 109.9-96.4=13.5 -- Westbrook’s difference is +19.1, meaning Oklahoma City is 19.1 points better with him on the floor than it is with him on the bench.

This basically summarizes what we already know: Westbrook is Oklahoma City, especially recently, with Victor Oladipo out with a sprained wrist.

It also tell us that Westbrook drastically improves the offense, 109.9 to 96.4, but despite not being considered a good defender, the Thunder improve on defense too, holding opponents to a not-super-impressive 104.2 compared to a horrendous 109.9.

That’s where it gets tricky, because there’s an important point within those defensive numbers, and it’s the essential problem with on-off splits. Westbrook generally plays with the first team, who just so happen to be OKC’s best players, and the stat covers the entire offense and defense, not just him.

So while OKC absolutely improves defensively with Russ on the floor, that really isn’t saying much when the team is as bad as it is without him.

Let’s compare this to the stats of another prominent dude: Giannis Antetokounmpo:

MIL with Giannis on the floor   MIL with Giannis off the floor
  Offensive rating ... 109.3     Offensive rating ... 101.6
  Opponents offensive rating ... 103.3     Opponents offensive rating ... 110.0

Again, this mostly reinforces what we already know. The Greek Freak is really, really good, and he might be as talented defensively as he is offensively.

The difference here comes out to be +14.4.

One random odd note is the Bucks are actually a tiny bit worse as a rebounding team with Giannis on the floor. Their total rebound figure is 50.2% with him off and 50.1% with him on. Obviously, that’s not even a negligible difference, but it's weird that it’s even that close.

Check back tomorrow for more numbers!

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