A weekly sketch show produces a new hour of comedy on a fixed deadline, which is a manufacturing problem as much as a creative one. The solution is deliberate overproduction.
Far more is written than can air
Writers submit many more pieces than the show has room for, and most are rejected before anyone performs them. Volume is the mechanism, not a symptom of inefficiency.
Comedy is unusually hard to evaluate on the page, so the only reliable filter is putting material in front of people and observing what happens.
Overproduction makes that filter possible, since a show that wrote exactly enough would have to air whatever it wrote. The surplus is what buys the right to be selective.
The read-through is the first cut
Scripts are read aloud to the cast and staff in a single long session, and the response in that room removes a large portion of the submissions immediately.
A read-through is an imperfect test because it rewards material that reads well and can undervalue pieces dependent on visuals or performance.
Producers account for that by protecting some sketches through to rehearsal, where the visual element can actually be judged.
Dress rehearsal decides the running order
Surviving sketches are performed in full before an audience shortly before broadcast, with costumes, sets and cameras in place.
The response there determines what airs, in what order, and what is cut for time, which is decided in the gap between the two shows.
That is why a sketch can be fully built, staffed and rehearsed and still never be seen, having lost to a piece that tested better. Cut sketches are a routine cost of the format rather than a failure of it.
Production runs in parallel with writing
Sets, costumes and prerecorded segments must be built for material that may not survive, which means the show pays for work it will discard.
Prerecorded pieces are shot earlier in the week, which gives them more polish and makes them the most reliably finished part of the hour.
Live sketches carry the risk instead, and the visible seams of a fast changeover are part of what the format trades for immediacy.
Topicality forces the deadline structure
A show responding to the week cannot write far ahead, so the schedule compresses everything into a few days by design rather than poor planning.
Late rewrites continue until minutes before broadcast, and cast members frequently receive changed pages after dress.
The result is a format where the deadline is the creative constraint, and removing it would change the comedy entirely. Material written over a month would be more polished and much less alive.