A screenplay is read faster than it is watched. Dense paragraphs slow a reader down, and a reader who slows down starts skimming, which means your best moment gets skipped. White space is not a stylistic preference; it is pacing you can see from across the room.
Write only what a camera could record. 'She remembers the summer her mother left' is unfilmable. 'She stops. Doesn't touch the door handle' is filmable and carries the same weight when the context is built.
Control attention by controlling paragraph order and length. A one-line paragraph lands like a cut. Bury a reveal in the middle of a five-line block and it disappears. Professional pages are edited on the page, not just in the edit suite.
Formatting discipline reads as competence before a single line is judged. Consistent sluglines, no camera directions unless the story genuinely requires them, correct character introductions, and a clean title page all tell a reader you have done this before.