The first four seconds set the price of a possession

Early clock efficiency is the largest gap between teams that almost nobody defends as a separate problem.

Split any team's offence by the shot clock and the same shape appears. Attempts in the first six or seven seconds are worth far more per shot than attempts in the last six. Everybody knows this. Very few defences are organised around it.

The reason the early window is so profitable is not that players suddenly shoot better. It is that the defence has not finished existing yet. Matchups are unresolved, help positions are unoccupied, and the rim is guarded by whoever happens to be nearest, which is frequently a guard with no business being there. A shot taken into that mess is uncontested in a way no half court action can manufacture, and it comes without the turnover risk that four passes of ball movement carries.

Which means a defence has a choice about where to spend its attention. Most spend it late. Practice time goes on pick and roll coverages, on rotations, on tagging the roller, all of which apply to possessions that have already survived the dangerous part. Whole staffs are employed to shave a hundredth off half court efficiency while the first four seconds are handed over to habit.

My argument is that the early window should be coached as its own defensive scheme, with its own rules and its own personnel. Not run back and match up. Something specific. The centre goes to the rim regardless of who he was guarding. The wings take the corners rather than the ball, because the trailing three is the shot a break actually generates once the paint is protected. Cross matches are accepted and resolved at the next dead ball rather than fixed on the fly, which is when the damage happens.

Some coaches will say that leaves you switched into terrible mismatches. It does, sometimes. A mismatch in the half court costs you a fraction of a point in expectation. An uncontested layup costs you well over one. That is not a close comparison and I do not understand why it keeps being treated as one.

The team that decides its early clock defence in advance is playing a different sport for four seconds a possession. Over eighty possessions, that is where the game goes.