OUT OF AMERICA: Early on in Michael Mann's just-released film biography of Muhammad Ali, the young boxer is sharing a private moment with his first wife, who asks him about his brief if well-chronicled encounter with The Beatles at Miami's Fifth Street Gym in the days before the first Sonny Liston fight.

While Will Smith's Ali doesn't specifically invoke John Lennon's name (he calls him "the guy with the glasses"), he recalls a semi-mystical piece of what was apparently guru-to-guru advice: "The more real you get, the more unreal it's gonna get."

The same, alas, might be said of director Mann's attempt to stuff a pivotal 10 years of Ali's life into a two-and-a-half hour docu-drama that is (as Ali's real-life physician and sometime cornerman, Dr Ferdie Pacheco, pointed out) neither fish nor fowl.

That's the whole problem in dealing with larger-than-life figures (and who is more so than Ali?) whose lives have been well chronicled. If you strictly adhere to historical truth, you're merely presenting the familiar, and if you start cutting corners for dramatic impact, what you're left with is imperfect history.

Toward the end of Ali, for instance, there is the tempestuous scene where Belinda Ali, the boxer's second wife, flies into Zaire and presents herself indignantly at the hotel suite he has been sharing with Veronica Porche, who would eventually become the third Mrs Ali.

That happened pretty much as it was depicted, but it happened in Manila in 1976, fully two years after the final credits have rolled.

Released on Christmas Day in the US, the film is framed between two significant bouts - the run-up to the then Cassius Clay's 1964 conquest of Liston in Miami Beach, where he won the heavyweight title for the first time, and the denoument of Ali's KO of George Foreman in their 1974 "Rumble in the Jungle" a decade later.

Smith reportedly trained as a boxer for two years (he must have spent at least as long studying the vocal patterns of the young Clay) in preparation for the role, and it shows. As the photographer Howard Bingham, Ali's long-time best friend who served as the executive producer for the film, told me a few days ago, "Put it this way: nobody who's seen it will ever mess with Will!"

If Smith's portrayal of Ali is effective, his ring performances are stunning. Mann assembled a cast of real-life boxers to portray Ali's opponents in the selected fights included in the movie - Michael Bentt as Sonny Liston, Alfred "Ice" Cole as Ernie Terrell, James Toney as Joe Frazier, and Charles Shufford as George Foreman - and while many of the fight sequences are meticulously and accurately choreographed, the truth of the matter is that Smith boxes more like Ali than any of the real fighters succeed in mimicking their counterparts.

Bentt, for instance, is perfect in his portrayal of the brooding Liston - right up until the opening bell, when he assumes a style that owes more to Frazier. Smith, on the other hand, has the Ali moves down perfectly, from the sixth round in Miami (when, having recovered from his temporary blindness, he out-jabbed Liston so badly that the bigger man quit on his stool a round later) to the Rope-A-Dope in Zaire.

The film makes some fairly generous assumptions. Liston, recognising that he is about to lose the Miami fight, orders trainer Yank Durham to coat his gloves with "the evil potion", which he then clumsily rubs into Ali's eyes. And the phantom "anchor punch" with which Ali felled Liston in their Lewiston (Maine) rematch a year later grows, in the film, into a devastating roundhouse right.

At the same time, Ron Silver's Angelo Dundee is merely a white guy in the corner with scissors in his pocket and Q-tip behind his ear. An innocent bystander watching Ali might easily conclude that the presence of Drew "Bundini" Brown (in truth a harmless court jester) in the corner was at least as important as that of Dundee - and the movie barely hints at the real-life animosity between the two.

In the Foreman fight, Dundee and Bundini are simultaneously jabbering at the fighter between rounds, and it's hard to tell which cornerman Ali is actually paying attention to. (In Zaire, of course, it was neither.) And Pacheco, who authored a somewhat scathing review of Ali for his hometown Tampa Tribune last week, is somewhat bewilderingly (since to the best of my recollection he doesn't utter a single intelligible line) portrayed by Paul Rodriguez in the film.

In the film, Ali's career fast-forwards from his 1971 loss to Joe Frazier to 1974 Kinshasa, a leap which overlooks the fact that he had 14 fights in between - including a loss to Ken Norton and a win over Frazier.

On the other hand, Mann makes no attempt to gloss over Ali's shameful treatment of Malcolm X, or of the infidelities which led to a parallel career as a serial husband.

The fact that Ali sacrificed over three years that would have represented the prime of any boxer's career in his lonely battle against the government over Vietnam is so hastily treated in the film that it becomes almost irrelevant.

In his lonely exile, Ali represented a charisma-soaked cultural icon for those of us who shared his opposition to the war, and a despised and controversial figure for the rest of America.

I mean, when I heard Ali say "I ain't got no quarrel with them Viet Congs," I can remember pumping my fist in the air and whispering "Go get 'em, kid!" But in the film, the line is coupled with another Ali-ism - "No Vietcong never called me nigger" - which at once alters the entire sentiment into a clumsily overstated throwaway line and, at the same time fails to grasp the absolutely incendiary response the two statements elicited from mainstream America at the time.

While Jon Voight perfectly mimics the voice and mannerisms of the arrogant broadcaster Howard Cosell, the Cosell of this movie is a warm, wise father figure, not the bitter, vindictive, and self-promoting man he actually was. Moreover, Mann's Cosell assumes the role akin to that of Macbeth's witches, omnisciently interpreting the future for the protagonist.

"They're coming after you," Cosell warns Ali. "They're afraid of black militancy in the inner cities."

When Smith's Ali repsponds that he does not represent the more militant strains of black radicalism and invokes the names of H Rap Brown and Stokely Carmichael, the wise and all-knowing Cosell has the last word.

"All they are is political," Cosell reminds him. "You're the heavyweight champ of the world."

I winced when he said that. Great theatre. Bad history.