The best rim protectors get penalised for the shots that never happen

A centre who scares drivers into stopping short generates no blocks and no defended field goal attempts, which the numbers read as absence.

The way to look good in rim protection statistics is to allow drives and then contest them. Every contest is an event. Every event gets counted, and if a decent share of those shots miss, the defender's defended field goal percentage at the rim looks excellent.

The way to actually protect a rim is to make guards decide, twenty feet out, that going in there is not worth it. That produces no events whatsoever.

This is a measurement problem with a real cost, because it changes which players get valued. Deterrence shows up as an absence: fewer attempts at the basket by the opponent, more pull ups from the short middle, more passes out that had not been planned. Those are team level effects diffused across a whole possession, and they get attributed to nobody in particular. Blocks and contests are individual, legible, and end up on a contract.

There is a second distortion inside the same numbers. Defended field goal percentage at the rim depends heavily on who is shooting. A centre who defends a lot of attempts by small guards will have a better figure than one who spends his night against a physical forward, and neither of those facts is about the defender. The raw statistic has no opponent adjustment in most public versions.

And a third: some of the very best deterrents give up a specific, chosen shot. They sit back, cede a floater, and defend the rim behind it. Floaters are lower percentage than layups, so this is often good defence, and it registers in the data as a defender who is not at the rim.

What would help is a possession level view. How often did the opponent get all the way to the restricted area at all, with this player on the floor and off it, adjusted for who else was out there. That is close to what good on off analysis tries to do, and it is noisy for individual seasons, but it is at least pointed at the right question.

The player who never blocks anything and whose team gives up nothing inside is doing the job perfectly.

He will lose the award to somebody who is worse and gets his hands on more basketballs.