Paul Giamatti, the unlikeliest leading man of his generation, is perfectly cast in “Barney’s Version,” an intimate relationship epic based on a Mordecai Richler novel. It’s a dream role for the balding, paunchy Giamatti, who manages something like a tour de force as this neurotic, self-loathing/humanity hating Jewish-Canadian TV producer who attracts and discards a trio of gorgeous women over the course of his tortured adult life.

It’s Richler’s semi-autobiographical tale about a sour-faced Canadian TV producer who reflects back over his life even as he is forgetting that life.  And Giamatti, when he isn’t swallowing his lines in guttural tones so low and internal that only he can make out what he’s saying, is bang-on in his take on a brilliant fellow who doesn’t suffer fools or anyone else gladly.

Consider his profession, as head of Totally Unnecessary Productions, home to the decades-running TV soap, “O’Malley of the North.” Barney drops that “Totally Unnecessary Productions” name to a striking woman (Rosamund Pike) he meets at his second wedding.

“It is and they are.”

He lives to interrupt his least favorite actress, a dizzy blond complainer who who plays a nurse (Macha Grenon) on the show.

“To let you finish that fought would be an insult to stupidity.”

Barney, son of a cop (Dustin Hoffman, hilarious), is not an easy man to like, much less love. He drinks too much, enjoys too many cigars and loses too many evenings to hockey games. Well, this is Montreal, after all.

He never should have married his free-spirit first wife (Rachelle Lefevre). But she was pregnant. And he’s a disappointment to his snooty second wife (Minnie Driver, on the mark). He’s doomed to let down the woman he meets at that second wedding, the one he wanted to run away with, right then and there. Barney isn’t always there for Miriam, that third wife, given a sympathetic, long-suffering object-of-desire fatalism by Rosamund Pike.

Barney and the narrative of this tale are all over the place. We have the present as Barney deals with a new, nasty book about him and his involvement in a long-ago disappearance, a book written by an obsessed cop (Mark Addy). We have the past, the tragedy of that first marriage, the ill-fated second coupling and the long, strained yet worshipful love that he displayed in the third. And we have the future, where Barney is headed at the end of his “version” of life.

Richler’s ability to connect these disparate threads on the page was a formidable challenge. Filmmaker Richard J. Lewis does the literary work justice, but it’s a struggle as we’re dizzily bounced from Montreal to New York to Rome (Barney’s honeymoon city of choice).  Lewis has his hardest time weaving in the whole disappearance/mystery into all this relationship stuff, including motive and a version of the moment of truth, neither of which we believe. Coherence is sacrificed to make way for stunts — sneaking in famous Canadian filmmakers Atom Egoyan and David Cronenberg for cameos as TV directors.

But Lewis does give his actors the chance to flower as characters, from Giamatti, Driver, Pike and Hoffman on down to Saul Rubinek, funny and narrow minded and cryptic in a scene as the father of Barney’s troubled flower-child first wife.

Giamatti’s liveliest scenes are with Hoffman, who twinkles through his turn as a coarse but charming working class cop who endured anti-Semitism and the loss of a beloved wife. Now retired, he’s still giving his adult son “Go with your heart” advice, even if that advice seems to fly in the face of morality and simple right and wrong. Driver gives a sassy snap to her Jewish Canadian princess role.

“Barney’s Version” is a messy movie, the odd emotional moment sneaking in around rank melodramatics. And if that sounds a little like life itself, that’s kind of the point. Melodramatic, impulsive, painful, but never quite “totally unnecessary.”

See for Yourself
“Barney’s Version”

Cast: Paul Giamatti, Rosamund Pike, Minnie Driver, Dustin Hoffman

Director: Richard J. Lewis

Running time:  2 hours 12 minutes

Rating: R for language and some sexual content