You certainly hope that the humility Mike Tyson is showing these days is genuine and not just an act.

"Tyson" suggests that the former is true — that the seeming contrition he's been exhibiting is real. And what's more, the film shows that this supposed "kinder and gentler" demeanor may suit the disgraced former heavyweight boxing champion.

Of course, James Toback's engrossing documentary profile of Tyson is certainly not an easy movie to watch. Though it is a well-assembled, confident piece of filmmaking, it might not appeal to anyone who's not a fan of boxing, a so-called "gentleman's sport."

Screenwriter/director Toback attempts to show how Tyson, a bullied and shy, self-described "poor kid from Brooklyn" became one of the most dominant figures in boxing history. He also shows what contributed to his eventual fall from grace.

Both the film and Tyson give considerable credit to Cus D'Amato, an aging boxing manager who provided the young pugilist with a much-needed father figure.

And the film makes a strong case that Tyson's fortunes changed for the worse once D'Amato died.

After all, the years that followed saw Tyson living a "rock 'n' roll" lifestyle — including an ill-fated, eight-month marriage to actress Robin Givens and culminating in a three-year prison stint on a rape conviction.

Though Toback ("Black and White") does use a lot of archived footage of Tyson's fights and press conferences, the film is still very reliant on Tyson himself. There are long interview portions and scenes in which he appears to narrate what's being shown on the screen.

That wouldn't work if he weren't such a fascinating figure. Again, the documentary might not appeal to anyone who's not interested in boxing. But those who are will definitely find a lot to like here.

"Tyson" is rated R and features some strong violent action (boxing scenes and fisticuffs, some of it very brutal), strong sexual language and references (profanity, vulgar slang and other frank sexual talk), references to recreational drug use (narcotics), derogatory slurs and language (some dealing with race and ethnic heritage, as well as sexual orientation), and brief gore and blood. Running time: 90 minutes.