Setting screens is the quietest contact sport on the floor

A centre who screens forty times a night absorbs a collision load that no public statistic records and no minutes limit reflects.

Forty collisions. That is a reasonable estimate for a starting centre in a heavy pick and roll offense, and every one of them involves standing still while a moving human being runs into your shoulder, hip or sternum.

Nobody counts it. We count rebounds, we count minutes, and we have GPS-style tracking that counts distance covered and top speed, all of which describe a completely different kind of stress. The screen is static loading followed by an immediate acceleration into the roll, which is close to the worst combination for soft tissue, and it happens on possessions that look calm on television.

The consequence is that a big man's fatigue arrives without warning signs the staff are watching for. His distance numbers look modest. His high-speed running is low because he barely does any. On paper he is the least worked player in the rotation, and then his hip gives out in week twenty and everyone calls it bad luck.

I would argue the fix is partly tactical. If you have one screener taking all forty, you have built a single point of failure into your offense, and the cheap remedy is to make wings screen more often. Guard-to-guard screening is not exotic. It also happens to be harder to defend, since the switch it invites does not create the mismatch the defense wants.

There is a counterargument I take seriously. Screening ability is a real skill, the angle and the timing are learned, and spreading the job around dilutes it. True. But a diluted screen from a healthy team beats a perfect screen from a player who is not out there.

The other unrecorded load is the seal. Once the roll is dead, a centre often finishes the possession leaning into a man in the paint for four or five seconds, which registers on no tracking system as anything at all because he covered two feet of ground. Isometric effort is invisible to every measurement device football and basketball currently use, and it is the most fatiguing thing a large man does.

The player who never appears on the injury report until he is gone for eight weeks is usually the one holding still while everyone else runs.