Defensive metrics and a classic announcer cackle
Thought Of The Week: Defensive Metrics
Note: All metrics below are from FiveThirtyEight, Basketball-Reference, or dunksandthrees, unless otherwise noted.
Defensive stats are a mess for reasons that are, by now, well-understood:
Albert Einstein never tried to contest Wilt at the rim, but his old chestnut describes the situation perfectly: “Not everything that can be counted counts, and not everything that counts can be counted.”
So much of defense is in the nuance: the proper positioning that makes a ballhandler’s drive just a bit more circuitous, forcing a tougher pass; the rim protector’s anti-gravity, forcing a shot from six inches further away than might have happened otherwise; the off-ball magnetism that crowds a pass receiver, putting them in a slightly more awkward spot on the catch.
Thanks to the increasing prevalence of reliable tracking data, we're getting better at measuring these things. Still, we haven’t come close to solving the fundamental issue: how do you reliably determine whether a player is good or bad at defense when you’re trying to compare them to every other NBA player?
It’s challenging, but it hasn’t stopped people from trying. Over the last few years, a whole host of advanced defensive metrics have popped up. I’m particularly interested in the all-in-one numbers that purport to distill a player’s entire defensive impact into one (often inherently meaningless) number.
Interestingly, advanced offensive all-in-one metrics pretty much arrive at the same conclusions with only slight differences in opinion. For example, one might have Luka Doncic as the best offensive player in the NBA, while another might have him second, but they’re all in agreement that Luka Doncic is really, really good at offensive basketball.
Defensively, however, these same metrics often are often in vehement disagreement. Right now, depending on what you look at, the best defender in basketball* is either Brook Lopez, O.G. Anunoby, Anthony Davis, or Nikola Jokic (yes, really).
For a further example, take controversial Bulls forward Patrick Williams.