The general wisdom in the NBA is that rim protection is extremely valuable, which is why someone like Omer Asik got paid by the Houston Rockets $24 million over three years and why the New Orleans Pelicans were willing to part with a first-round draft pick to pair him up with Anthony Davis.Roy Hibbert, before his performance fell off a cliff, became the poster boy of protecting the rim and the term “verticality” became a part of the every day NBA fans dictionary.
So how big a part of your defense is protecting the rim?
First we take into account last season’s numbers in opponent field goal percentage at the rim, the number of attempts within three feet from the basket and defensive rating. Based on that data an expected defensive rating can be modeled, with weighted values for how important being good at limiting attempts and makes is.
The function for the regression model is: EXPECTED DEFENSIVE RATING = 0.47 * OPPONENT PERCENTAGE + 0.60 * OPPONENT ATTEMPTS + 0.7662065407
Where opponent percentage and attempts are expressed as rankings, No. 30 being the best and No.1 being the worst.
This is to create a ranking of relative values of where you expect to be in defense compared to the rest of the league.
The chart above shows how your expected defensive rating based on rim protection stats fares against actual Defensive rating. The correlation between the two is about 62 percent, meaning that based the value of defending the paint can explain over 60 percent of your defensive rating.
What’s notable is that at the very right side of the graph, the black and blue points are very close to each other and get further and further away from one another as you go to the left. This seems to indicate that if you want to be one of the best defenses in the league, protecting the rim becomes more and more important.
You could almost say that you can’t be a great defense without it.
Defense is literally half the game, and just as important as offense. Rim protection is over half of that defense, making it by far the most important aspect of building a great defense.
It’s not only about shot blocking. The Pelicans have a prolific shot blocker in Anthony Davis and had the most blocks in the NBA but ranked in the bottom five in both defending the basket and defense rating.
Good rim protection starts on the perimeter. If a an offensive player is able to just blow by the defender, it’s difficult to help quickly enough without leaving your man open for a dump-off pass near the basket.
The opposite example would be the Memphis Grizzlies, who did very well in protecting the basket despite being below average in blocked shots. Marc Gasol isn’t really a shot blocker, ranking 83rd in blocks per 36 minutes, but he’s an absolute beast in the paint.
Gasol is an expert at being in the right spot and using his entire 7’1″ frame to stand in correct position near the rim forcing tough floaters and lay-ups over him.
The most interesting team in regards to their defensive structure that relates to rim protection is the Portland Trail Blazers. The Blazers were the third-best team in opponent field goal percentage at the basket at 59.6 percent.
Despite that, they were only 16th in defensive rating. Portland’s conservative defensive schemes, where the big man hangs back at the foul line in attempt to force mid-range jumpers. Portland allowed the fifth most mid-range jump shots, and allowed teams to shoot the second highest percentage.
The Blazers don’t really have great individual defenders, especially when it comes to their big men, but their system was designed in a way to limit their big guys being exposed. It’ll be really interesting to see how they can still improve on defense. This is a case where perimeter guys like Batum (an overrated defender) and Lillard (below average) need to take the next step.
*Stats per Basketball-Reference.com.