Run Fatboy Run

Though “Run Fatboy Run” is genial and often amusing, I can’t help thinking it would have been funnier if a different combination of people had worked on it. Michael Ian Black (the writer), Simon Pegg (the star and co-writer), and David Schwimmer (in his theatrical directorial debut) are all funny guys, sure — but they’re each a different kind of funny. Black’s humor tends to be surreal and odd (see TV’s “Stella” and “The State”), while Pegg — best known for co-writing and starring in the spoofs “Shaun of the Dead” and “Hot Fuzz” — favors subtlety and wordplay. And for all we know, Schwimmer’s sense of humor might be limited to reading “Friends” scripts.

Their collaboration in “Run Fatboy Run” produces mixed results, a likable comedy with some rough edges but a lot of charm. Pegg plays Dennis, a hapless London bloke who is behind on his rent and has a dead-end job chasing shoplifters from a women’s clothing store. He also still pines for his ex-fiancee, Libby (Thandie Newton). Like a sweet but naive child, he can’t understand why Libby won’t let him back into her life.

“You left her at the altar when she was pregnant,” his friend Gordon (Dylan Moran) points out.

“But that was ages ago!”

“Women remember that stuff.”

Indeed they do. Now, five years after Dennis got cold feet and fled their wedding, Libby is dating Whit (Hank Azaria), a handsome and successful American financier. Whit is Mr. Perfect, and he runs marathons, too, an activity that the sedentary Dennis — out-of-shape, nicotine-addicted Dennis — cannot fathom. Yet in an effort to prove to Libby that he is a changed man, he announces that he will run an upcoming marathon, too. He has never finished anything before in his life, but he will finish this!

Finish the race, get the girl. It’s silly and formulaic, and I think Michael Ian Black knew that when he conceived it. I suspect he intended it as an ironic goof before letting it get bogged down in plot details. We wind up with two side bets on Dennis’ marathoning, one involving Gordon’s gambling debts and the other centered on Dennis’ late rent, and neither one is plausible or necessary. A Screenwriting 101 teacher might say that the script MUST have an antagonist who doesn’t want Dennis to finish the race, but common sense should argue that Whit, and Dennis’ own complacency, are his opponents. The other interpolations are superfluous.

Schwimmer sometimes goes for the easy joke, often resorting to clunky slapstick. I’m talking about little things like cops tackling Dennis for no reason (he wasn’t resisting, nor was he committing a serious crime), or Dennis falling down after being hit in the head with a shoe. In the aggregate, Dennis falls down way too much. As a director, you have to ask yourself: Why is this character falling down? Is it because there’s a good reason for him to fall down, or is it just because I think it’s funny when people fall down? If it’s the latter, you need to stop and re-calibrate.

But then there’s Simon Pegg, whose output is more consistently funny than that of anyone else involved in this production. He sticks to his strengths as Dennis, making him frustrated but sympathetic, smart but not brilliant, and luckless but not a loser. You see it best in Dennis’ scenes with Jake (Matthew Fenton), the 5-year-old son that Libby was pregnant with on their botched wedding day. Pegg interacts with the kid as if they were equals, and you realize it’s impossible not to like a character who treats children with such compassion and good humor.

With support from British comic Dylan Moran, who earns laughs as Dennis’ shabby, devil-may-care best friend, “Run Fatboy Run” is commendable if not exactly memorable. Could a better combination of collaborators have produced something greater? Definitely. But this cheerful mix of juvenility and grown-up-relationship angst goes down smoothly enough to be worth watching.

B- (1 hr., 35 min.; PG-13, some profanity, crude humor, and brief partial nudity.)