Basketball Stacks part 2: Rebounding

Yesterday, I posted a new idea for visualizing box scores: Game Stacks. While the first version did a good job of showing shooting percentages and turnover rates, it didn’t do a good job on rebounds. As my pops pointed out, Indiana had a big rebounding advantage over Michigan by the basic numbers (36-22), so it seemed wrong to rely only on the height of the stacks to determine who rebounded better. The reality: Michigan got more chances not because they rebounded better, but because they had more misses — and you have to miss to get a second chance. The height of the stacks just showed that Michigan got more offensive rebounds, even though their rebounding rate was terrible.

So, round two. Here’s the Michigan-Indiana Game Stack redesigned to capture rebounding:

Michigan at Indiana 2-2-2013

Without play by play data, I had to keep the rebounding simple — I figured out the offensive rebound rate for each team:

Off reb rate = your off rebs/(their def rebs + your off rebs).

Then, I multiplied this rate by the relevant number of shots to generate the “Missed (O Reb)” category for each type of shot (the dashed regions). Each dashed/empty combo now visualizes the offensive rebound rate for the relevant team.

Now the picture is clearer:

  • Michigan got a couple extra chances, but they missed a lot of shots — their rebound rate was actually not good compared to Indiana’s
  • Not only did Michigan shoot a lower percentage on twos and threes, they hardly got to the line, lowering their efficiency even more
  • Indiana kept Michigan in the game by turning the ball over quite a bit

For completeness, I wanted to include the updated Game Stacks for Clippers at Celtics and Lakers at Pistons on Sunday:

Clippers at Celtics 2-3-2013

Lakers at Pistons 2-3-2013

In the Clippers-Celtics game, the Clippers actually did do well on the glass, which gave them a few extra plays. However, they wasted more chances on turnovers, and Boston got to the line more and shot better from three.

In the Lakers-Pistons game, the story was pretty similar, with the Pistons being the strong rebounding, inefficient team (turnovers were about equal in this game — the Pistons lost mostly because of their very poor shooting on twos).

Here’s a fun game stack from Tuesday:

Warriors at Rockets 2-5-2013

Whoa! The Rockets did a better job on the glass and committed fewer turnovers, giving them more chances. But the real story is the three point shooting. The Rockets made a lower percentage than the Warriors on twos, but tied the NBA record with 23 three pointers, and ran away with the game.

And finally, a big Michigan win, since I’m a homer:

Ohio State at Michigan 2-5-2013

A very close Game Stack — quite even on free throws and turnovers. Michigan picked up the rebounding compared with the Indiana loss. However, they shot a terrible percentage on twos. The Wolverines managed to overcome that by taking a lot of threes and making a great percentage, but it took overtime to do it.

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4 responses to “Basketball Stacks part 2: Rebounding

  1. Pingback: Visualization: Basketball Game Stacks | Causal Sports Fan

  2. Josh Hendrickson

    This is definitely one of the best blogs I read on a consistent basis. I think this game stacks idea is fantastic. I am not a huge basketball fan but was able to easily synthesize the stats from the game in a meaningful way just by quickly looking at the stacks. You rock Tyler. Thanks for keeping me entertained down here in NC!

  3. Pingback: Michigan: Destined for an early exit? | Causal Sports Fan

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