Tonight’s How I Met Your Mother was directed by Neil Patrick Harris. He won’t get many other opportunities to direct, since virtually every episode is directed by Pamela Fryman. (Similarly, Jason Alexander got to direct one Seinfeld and only one, because that show rarely used “guest” directors.) The self-directed episode is a TV tradition, usually handed out when actors want to stretch themselves, or when they get bored and threaten to leave (not a factor in Harris’s case) or when they are under-utilized.
The classic example of the last-named situation is Peter Bonerz, an extremely talented improv comic who was stuck with the unfunniest role on The Bob Newhart Show, playing the character whose job it was to a) Listen to Bob complain about the week’s problem or b) Star in episodes that no one liked. Realizing that he had very few lines in many of the episodes, he asked to direct an episode, learned on the job (both at his own show and some assignments on other MTM shows), and soon started directing any episode where his character didn’t have much to do. He directed 29 episodes of the series, including the finale. Hugh Beaumont directed 20+ Leave It To Beaver episodes, probably for the same reason: how much did Ward really have to do in front of the camera in any given episode?
The “stretch yourself” scenario happens when the actor starts to become more involved in the production of the show, and turns to directing as a way of exerting authority. Alan Alda was not a director before he started directing (as well as writing) episodes of M*A*S*H. As he became more of a creative force on the show, he directed more and more episodes, handling other people’s scripts as well as his own; he directed 32 episodes in all, or more if you count the series finale as several episodes in one long time slot.
Then there are actors who turn to directing because they’re bored with the show and the producers want to keep them happy. I may be doing Scott Baio an injustice, but I think of this as the likeliest explanation for why he directed 36 — count ’em, 36 — episodes of Charles in Charge. And he directed those 36 episodes in a span of only four years, and he had a lot of lines in most of them, which is why it doesn’t fit into the “under-utilized” category. It seems more like David Schwimmer directing 10 Friends episodes in the last half of the run: if the show isn’t much of a challenge any more, then the actor turns to directing as a way to keep occupied.
It’s interesting, though, that some actors who have directing ambitions do not carry out those ambitions on the show. George Clooney never directed an ER; Ron Howard was offered the chance to do Happy Days episodes but turned it down. Thomas Carter started his successful TV directing career while he was acting on The White Shadow, but Tim “Salami” Van Patten did not.
None of these guys can compare to the king of the self-directed episode, Ozzie Nelson. But as the director and writer and producer and owner of his show, he’s almost in a different category; he wasn’t an actor hired to appear on the show, he was in control of the whole franchise.