I’ve written hour episodes (or two-parters) for MASH, CHEERS, and FRASIER. And here’s what I’ve learned: They turn out to be 45 minutes worth of story and fifteen minutes of filler. The stories are generally too long to tell in a half hour, not long enough to sustain a full hour.
The “Goodbye Radar” episode could have easily been a half hour. But CBS wanted to make a big “Sweeps” event out of it so we had to concoct this whole generator-going-out business, which did nothing to improve the show.
Often times episodes don’t start out as hours (or two-parters) but the first drafts come in so overloaded with story that you decide to expand them. And then you find it doesn’t expand enough. So you toss in a B-story and just keep going.
Sitcoms have their own rhythm and method of storytelling. Again, to use MASH as an example, we would normally tell two or three stories and pack each scene with as many jokes and quips as we could – to the point where we would often think it’s silly. Radar would enter the Swamp and Hawkeye would have to have a smart remark. I used to say, “What if, just once, and I know this is daring, he just said HELLO?! Y’know, like a normal human being?!” We got away with it in the half hour format but when we stretched the show to an hour the stylistic seams really started showing, and it felt like overkill.
But at the end of the day, these are writing issues and if you expressed them to the network they would laugh. Longer episodes mean more commercial time to sell, something special to promote, and one less half hour of a show that isn’t as popular. And for your series finale they want two hours. They just never realize that by forcing you to do hours along the way they hasten that finale by two or three years.