Screen, Line, Defender is a processing sequence used on perimeter screening plays, especially pick-and-pop situations that free a shooter for a jump shot.

This sequence helps officials organize what they must judge:

1. Screen
   • Is the screener legally set?
   • Did the screener cause illegal contact?
   • If the screen is illegal and creates an advantage/disadvantage, an illegal screen should be called
2. Line
   • If the screen is legal and the shot goes up, determine whether the attempt is a two-point or three-point shot
3. Defender
   • Judge the defender contesting the shot
   • Is the contest legal?
   • Is there illegal contact that affects the shooter?

This sequencing helps officials avoid missing the first illegal act on the play. If the screen is illegal, that must be ruled before moving on to the rest of the action. Many perimeter plays happen quickly and include several actions at once. A structured visual sequence improves consistency and accuracy.

Officiating focus:

Judge the screen first. If it is legal, move to the shot line and then to the defender contesting the play.