After posting my adjusted defensive impact metrics yesterday, I said this on Twitter:
I was referencing the bars at the bottom of each player’s chart. Before I continue, let me explain how to read these. Here is Al Horford:

This means that when Horford is on the court as a defender, the probability that any given shot will be a close shot (which I define as <8 feet from the basket) is increased by 2%. The probability that any given shot will be a midrange shot is increased by 4%, and the probability that any given shot will be a 3 is decreased by 6%. These should sum to 0, although occasionally they may not due to rounding.
Now take another look at the adjusted defensive impact charts and compare, for example, Roy Hibbert to Paul George or, as @gswhoops mentions, Andrew Bogut to Andre Iguodala. The results show pretty consistently that big men tend to alter where an offense takes its shots. Wing defenders don’t. @WhrOffnsHppns asked if this might be a consequence of the method and as I sat at my work computer, with no access to my code, I realized that I couldn’t even really remember what the method was. I implemented this weeks ago and then just kinda forgot about it. So below the cut I outline the method in detail and look at some descriptives to buttress the big man findings. The short version though is that I do not think these results are just an artifact of the method and I want to double down on what I think is a true finding: “Interior defenders affect opposing shot location. Wing defenders don’t.”
Continue reading →