The screen that never happens is the one that works

Ghost screens beat good defences because defenders react to the shape of an action rather than to contact.

Watch the defender, not the screener. He starts moving before contact is made, and that is the entire exploit.

A ghost screen is a screen that is never set. The offensive player runs at his teammate's defender as if he intends to make contact, then slips away toward the arc at the last instant. Nothing touches anybody. And yet the defence has usually already switched, or already gone under, or already begun a hedge, because those decisions have to be made early to be made at all. Contact is confirmation, not the trigger.

This is why the action is so hard to guard for well drilled teams specifically. The better a defence is at communicating, the earlier its calls go out, and the earlier the call goes out the more useful it is to give a false signal. Sloppy defences are almost immune, in the sense that a man who was never going to switch cannot be tricked into switching. There is a real coaching joke buried in that.

The obvious use is to get a switch you want. Run your best shooter at a slow big, take the switch, isolate. Fine, everybody does that. The version I find more interesting is the opposite, where the ghost screen prevents a switch. The screener sells the action hard enough that the defence stays attached to its original assignments in anticipation of contact that never arrives, and the ball handler simply drives past a defender who has flattened out and is now half a step behind.

There is a cost, and it is not tactical. It is credibility. Ghost the same screen four times and the fifth one gets ignored, so you have to actually set one occasionally, and the one you set must hurt. This is exactly like a bluff in any other game, a comparison I would normally avoid because it usually explains nothing, but here the structure genuinely is the same. You pay for future deception with present contact.

My complaint is that most teams treat it as a special, a wrinkle saved for the fourth quarter of a playoff game. It should be baseline vocabulary. If your fives cannot set a real screen anyway, and plenty cannot, then stop pretending and make the fake into the plan.