Free throws are practised in the only conditions that never occur

Nobody misses at the end of an empty gym; players miss tired, loud, and after a hard foul, which is the state nobody rehearses.

Two hundred in a row after practice, alone, unhurried, hitting eighty five percent. Then February, fourth quarter, the crowd behind the basket doing what crowds do, legs at the end of a back to back, one and one after taking a forearm to the chest. Different task entirely.

Free throw shooting is the most closed skill in the sport, which is exactly why the failures are almost never technical. The stroke is fine. The conditions have changed and the conditions have never been trained.

Fatigue first. A tired shooter's legs give less and the ball comes up short, and the compensation, unless it has been rehearsed, is to push harder with the arms, which is how a good shooter finds the front rim three times in a quarter. If he has practised at the same heart rate he will already know his line is a fraction flatter and will adjust without thinking. That takes maybe ten shots a day, taken deliberately after the hardest block of the session rather than at the end of a cool down.

Noise second. It is trivially easy to pipe crowd audio into a gym and almost nobody bothers. Routine is a rhythm, and rhythm is easier to hold when you can hear yourself. If a player has only ever bounced the ball three times in silence, the first time he cannot hear the bounce is a live experiment.

Consequence third, and this is the one that gets dismissed as gimmick. Make the team run for a miss. Make him shoot with the group watching. Anything that raises the cost of a miss even slightly changes what the skill is being practised under, and it is the closest thing available to the actual pressure.

I will grant that some of this shades into superstition and that a bad free throw shooter is usually bad for mechanical reasons that no amount of noise will fix. That player needs a rebuild. My argument is about the eighty percent shooter who becomes a sixty five percent shooter in May, which is not a mechanical problem at all.

He practised the wrong version of the shot. Every day. For years.