HOW do you know when a film is horrible? When it’s How Do You Know, it’s pretty obvious.

Nothing about this would-be romantic comedy ever gels — neither the romance nor the comedy and, worst of all, not the characters.

Individually likable ordinarily, Reese Witherspoon and Paul Rudd make zero sense together here as a couple. Similarly, the duelling story lines that comprise the script feel slammed together, so the film as a whole never finds a groove — which only accentuates the fact that it’s overlong.

Most shockingly of all, How Do You Know comes from someone who should know better: writer-director James L Brooks, who’s repeatedly proven himself more than capable of finding just the right tone or the perfectly poignant turn of phrase in films like Broadcast News, As Good As It Gets and his multiple Oscarwinner Terms of Endearment. Here, everything feels off, as if the lightness required of the genre eluded him. It is, however, shot flatteringly — the work of frequent Spielberg cinematographer Janusz Kaminski.

Witherspoon is a beacon of perky determination as Lisa, a longtime professional softball player who suddenly finds herself cut from the US team at age 31. Not knowing what to do with herself now that the thing that defines her has been taken away, she bounces back and forth between Matty (Owen Wilson), a stud pitcher for the Washington Nationals (a bit of casting that isn’t believable for one second) and George (Rudd), a corporate executive under federal investigation for financial crimes he didn’t commit.

How Do You Know similarly bounces back and forth between Lisa’s boyfriend confusion and George’s attempts to clear his name with help from his extremely pregnant assistant (Kathryn Hahn) and without much help from his short-tempered father, played by Jack Nicholson. The frequent Brooks star, who won Oscars for As Good As It Gets and Terms of Endearment, appears in maybe a half-dozen scenes, tops, and looks completely uncomfortable and uninterested the whole time.

Here, Nicholson doesn’t get to have the sort of sweet, youmake-me-want-to-be-a-betterman moment that so often marks Brooks’ best work. That responsibility falls to Rudd, whose character tells Witherspoon’s that any man who loves her should love her for who she is, just as she is. Trouble is, it’s hard to know who Lisa is — she’s devoted her whole life to her sport, she has a bunch of little sticky notes all over her bathroom mirror with pat platitudes about character and heart, and that’s about it.

Wilson’s character, a version of the confident but clueless goofball he so frequently plays, is vaguely more interesting because at least he knows who he is — an arrogant, womanising jock — and he’s comfortable with that. Rudd’s George, meanwhile, goes all soft and gooey early and often, falling for Lisa out of nowhere after an awkward blind date. The comic edge that makes Rudd so appealing is gone; it doesn’t help his cause that treacly music pipes in every time he says something even slightly meaningful. Because otherwise, how would we know it’s meaningful?

How Do You Know, a Columbia Pictures release, is rated PG-13 for sexual content and some language. Running time: 116 minutes. One star out of four.