Truth behind Chris Bosh’s rebounding numbers

Right now, two things appear to be true. One is that unless Dr. House remembers something right this very instant (or at least within the hour), somebody will die. The other is that Chris Bosh is a terrific rebounder, the best in the league.

Why is that? Basketball-Reference is showing that so far this season, Bosh has 293 boards, both the highest on the Raptors and the NBA.

Table A – Total NBA Rebound Leaders

But in a vacuum, rebounds don’t mean a lot – they combine both offensive and defensive, which when you think about it, are completely different things: one gives you a possession while the other extends a possession, giving you another chance at a basket.

So let’s break them up. The bulk of Bosh’s boards are on the defensive end – as should be expected – but he also puts up good numbers on the other side of the court. His 94 offensive rebounds ties him with Zach Randolph for the NBA lead.

Table B – NBA Offensive Rebound Leaders

It’s also a team high, too.

Table C – Toronto Raptor Offensive Rebound Leaders

An aside. Remember what I said above? Look at Hedo Turkogolu’s numbers – he’s fourth on the team in rebounds, almost exclusively (90%!) from defensive numbers. How do the others look? About a quarter of Andrea Bargnani’s rebounds come on the offensive side, while about a third of Bosh’s do. Amir Johnson though Almost half (44 per cent) of his come on the offensive glass. Neat.

But just looking at rebounds, it doesn’t mean much. Now if there was a way to put these in context…

Which there is: by measuring them against the Raptors’ missed shots and the other teams rebounds. Think of it this way. Each missed shot could result in an offensive rebound. What percentage of these potential rebounds is Bosh getting? And, most importantly, how does he compare to the other leaders (see Table A).

As of last week, the Raptors have taken 1949 shots and missed 1049. Opponents got 728 defensive rebounds from those shots, while the Raptors grabbed 271 offensive rebounds, for a total of 999 rebounds (the other shots? I assume they weren’t rebound-able. I won’t count them).

Let’s crunch some numbers.

Table D – Offensive Rebounding Percentage, Toronto Raptors

What do those numbers mean? When he’s on the court, Bosh grabs about 13 per cent of all the possible offensive rebounds. Bargnani, who nobody calls a good rebounder, grabs about five per cent.

But it’s Amir Johnson who stands out: his 15 per cent is pretty good – better than Dwight Howard’s (13.2). To be fair, Johnson’s numbers are skewed a little by his limited minutes (another skewed example: Pops Mensah-Bonsu’s 19.0 ORB%).

But how does Bosh compare to the rest of the league leaders?

Table E – Offensive Rebounding Percentage, League ORB leaders

Without digging too deeply into the numbers, looks like this: despite being tied for the most boards, Bosh doesn’t have the greatest offensive rebounding percentage; when it comes to extending a possession, he’s a tad behind the four players immediately behind him on the offensive rebounding chart.

Why does this matter? Offensive Rebounding Percentage is what’s known as a rate statistic: it measures the rate at which Bosh (and Randolph and Bargnani) grab rebounds. Essentially, it helps add context to the stats.

For instance, just looking at the leaderboard shows that Bosh is on top. It doesn’t show that he’s played over 100 more minutes or 100 more potential rebounds to grab this season than the other four.

And what does it prove? When you consider what his offensive boards mean to the team’s offensive rebounding percentage, his numbers don’t seem too bad – Bosh is in the top 10 for the NBA, I’d imagine – but they’re not as good as they seem, either.

It’s true he’s a good rebounder. He’s grabbed more off the offensive glass than almost anybody else, no easy feat.

But is he the best rebounder in the NBA? He’s not far off, but he’s not there either. In fact, he might actually be the second-best rebounder on his team.

Oh, and Dr. House? He saved the day, the person lived.

Note: All base statistics from Basketball-Reference.com.