Scouting reports go stale by the new year

The decision to go under a screen is usually made in October from last season's shooting numbers, and players change.

Go under. Two words from a coaching staff, delivered before the season starts, based on a shooting percentage from the previous year, and then repeated by a guard every night in January because that is what the report said. Meanwhile the man he is going under against spent the summer fixing exactly that shot and is now hitting it at a rate that would make him one of the better pull up shooters in the league.

This lag is real and it is longer than people assume. Shooting percentages are noisy, so a coaching staff that reacts quickly to a hot month is reacting to noise. A staff that waits for a reliable sample is waiting a very long time, because the sample size needed to distinguish a genuinely improved shooter from a lucky stretch runs into hundreds of attempts. Both approaches are defensible. Both are wrong a lot of the time.

What I would do is stop treating it as a shooting question and start treating it as a mechanics question. You do not need six hundred attempts to see that a player's release has changed, that his feet are set differently, that he is taking the shot in rhythm rather than reluctantly. A video coordinator can see that in November. A percentage cannot confirm it until March, by which time you have given away four months of open looks.

The same lag runs the other way and is even less examined. A shooter who has genuinely declined, through age or a wrist problem nobody has announced, keeps getting chased over screens for most of a season because his reputation is doing the defending for him. Reputations are extremely sticky in this sport. Coverage assignments should not be.

There is a self fulfilling loop in it too. Go under enough times and the player either learns the shot or stops wanting it. Chase him over enough times and he stops seeing that shot altogether and becomes a driver. So the coverage is not merely a reaction to a player, it partly creates what he becomes, and I do not think that gets weighted at all in how these decisions are made.

The practical upshot is unromantic. Revisit the report at the quarter pole, in writing, for every opponent. Most staffs revisit it when they get burned.