Napoleon once said that all generals fight the last war.
In the television business, you fight the last war by trying to correct the mistakes you made in the last episode you filmed.
If you're lucky enough to have had a series on the air - but unlucky enough to have had it cancelled - you fight the last war by correcting the mistakes you made the last time.
Either way, you're always a step behind. Fighting yesterday's war is no way to win today's. And worse, when you correct for errors - the last episode didn't have enough romance, had too much yelling, had too many puns, whatever - you almost always end up overcorrecting.
I've spent most of my career writing and producing television comedy of the most classic kind - the multiple-camera, live audience sort - and I really like it. I like the audience, I like the one-act play quality of the episodes, I like the sound of actual human laughter, and I like the discipline of telling a story with character and dialogue, rather than camera tricks and fast cuts.
Those kinds of television shows have been out of fashion lately. When I was growing up, they pretty much dominated the airwaves, classics like Fawlty Towers, The Mary Tyler Moore Show and the show where I started my career, Cheers.
They're making a slow comeback, but it's been a while since the heyday of the live-audience comedy. So though I love that form, it's also a little limiting. Certainly career-wise.
What people in Hollywood say about writers like me is: "He's a joke writer, from the old school."
That's the problem with having a prolific career in one particular form. When the form goes out of style, so do you.
So you end up fighting the last war.
I'm working on a new project that shoots very soon, and I'm acutely aware of how heavily my CV - filled with old-fashioned audience comedies - weighs on the expectations of my partners in this new project. It's for a hip and edgy television network, filled with executives in slim-cut suits. They're all young and ironic and irritatingly respectful. There's nothing more insulting than an ostentatiously complimentary 30- year-old.
The show itself is a very dark comedy. It's light-years away from the show I'm working on now - or, frankly, anything I've ever done before. And I know that the assorted hipsters at the network are aware of this, and that they're aware that I'm aware of this, and that we're all aware that the danger is that I'll overcorrect for my past, and deliver an entirely too weird, too dark and too off-putting unfunny comedy.
Which is possible. Even, I'm embarrassed to say, likely.
For instance, the show I'm producing now is a traditional comedy set in a neighbourhood pub. It's exactly the kind of comedy that has given me the "old school" reputation.
As I was editing a recent episode, I noticed the "atmosphere" (what laymen call "extras") were all a little - look, I'm just going to come out and say this, this is American TV, I'm not going to apologise - they were all a little drab looking. All a little unattractive. We needed what we in show business call "some eye sweets".
So I called the person in charge of this sort of thing and I issued an order that has been issued, verbatim, by more Hollywood producers than anyone could ever count. I said: "Can we please have more pretty girls on the set in the background?"
The next week, the set was entirely filled with pretty young girls. But they were too pretty and too young, frankly.
In other words, I had overcorrected the previous week's mistake.
And that is something I'm going to try to keep in mind on the dark comedy for the hip network. I need to remember not to worry too much about my CV. Because funny is funny, old school or not.
Rob Long is a writer and producer based in Hollywood
On Twitter: @rcbl