ThunderDAN asked me yesterday about isolations, how often teams used them and how effective they were. “Isolation” tends to carry a negative connotation in today’s NBA. It is true that they are often more inefficient than other variations of offense. For example, the HEAT had six types of offense that accounted for over 9 percent of their possessions last season. At .831 points per possession, isolations ranked dead last of those six.
That isn’t to say that all isolations are bad. Sometimes isolations are the safe, smart play. Isolations limit the risk of turnovers and allow the ball handler to dictate use of the shot clock, i.e. running it all the way down late in games. We’ve all seen LeBron James use a screen to gain a mismatch with a big man. When he gets the switch he wants, LeBron often briefly retreats before barreling down the lane. Is this scenario as efficient as an open Mario Chalmers three from the corner? No. But, it isn’t a bad option, and it’s often easier to come by.
Now, what we want to know is does a team’s offensive rating (points per 100 possessions) decline as the percentage of isolation possessions increases? Let’s take a look:
(click the image to enlarge)
In this graph, size and color are tied to isolation points per possession (ppp). The larger and darker a dot is, the more efficient the team’s isolation offense is.
As you can see by the trend line, yes, there is a negative relationship between offensive rating and percentage of possessions that are isolations. But, the Thunder and Clippers illustrate it is possible to use lots of isolations and have an extremely successful offense. The Magic and Knicks were polar opposites in terms of percentage of isolations used, but finished the season with virtually matching offensive ratings.
So the true answer to our original question is, “it depends.” That might be slightly disappointing, but it is also the answer to many of questions that pop up about basketball. It depends on a team’s personnel, their offensive system and the random bounces of an orange sphere on an orange hoop.
Data is from Synergy Sports and Basketball Reference
