A pressing trigger is a promise the team must keep

Pressing collapses when one player goes early, because everyone behind him has already committed to a shape he abandoned.

One striker decides the moment looks right. He goes. Nobody else does, because the ball was not actually at the trigger, and for the next eight seconds the opposition plays through a team that is neither pressing nor defending. That is not an effort problem. It is a communication failure with a clear author.

A trigger is a rule about when to attack the ball, and the point of a rule is that everyone applies it simultaneously. Common ones are simple: a pass backwards, a pass into a defender's weaker foot, a first touch that goes slightly long, a receiver facing his own goal. None of them are complicated. All of them require the whole unit to read the same cue at the same instant, which is why the best pressing sides look almost choreographed and the mediocre ones look frantic.

What makes this fragile is that the cost of a false start falls on somebody else. The striker who presses alone loses nothing personally; he looks committed. The midfielder behind him now has two passing options to cover instead of one and gets beaten, and it is the midfielder who appears in the highlight of the goal. So the incentive to gamble sits with the player who bears none of the consequences.

I think this is why good coaches spend so much time on when not to press. Restraint is harder to train than aggression, and it is the part that actually distinguishes a coherent press. A side that presses selectively and holds shape otherwise will concede fewer chances than a side that presses constantly, even if the constant presser looks more impressive for twenty minutes.

There is a counterargument about chaos, and it deserves a hearing. A disorganised press does generate turnovers, because opponents make mistakes under pressure regardless of whether the pressure is well structured. Fine. The question is the ratio, and the ratio for an uncoordinated press is bad enough that only teams with a large talent surplus can afford it.

The tell is what happens after the ball is lost. A structured press has a second wave. A gamble has one man walking back.

If your press is not working, look at whether the trigger is being obeyed before you look at how hard anyone is running.