Anyone who swallowed Will Smith’s recent assertion that no new superheroes have been introduced into the pop culture pantheon for over 40 years clearly hasn’t been paying close attention to TV’s “Heroes.” Anyone who believes we haven’t seen a postmodern reconstruction of the superhero mythos must have nodded off for the last act of “Unbreakable.” If the idea of rescuing a thankless citizenry only to be reviled and persecuted seems an ingenious new twist on the comic book formula, you might want to read “The Watchmen” or see Pixar’s “The Incredibles.” Those who believe the concept that superheroes could be modern embodiments of the immortal gods of old is a novel and original idea might take a closer look at Marvel’s “Thor” or D.C.’s “Wonder Woman.” If you think “Hancock” is the first time the big screen has offered a surly, boozy, unshaven street bum with amnesia as reluctant champion, you apparently missed Hugh Jackman’s Wolverine in all three “X-men” pictures.

So, apart from casting squeaky clean charisma king and walking role model Will Smith as a petulant, bourbon-soaked bad boy, what does “Hancock” hand us that we haven’t seen before? Of all the improbable concepts director Peter Berg (“The Rundown,” “The Kingdom”) lobs out to challenge an audience’s ability to suspend disbelief, the single original notion offered by “Hancock” may be the introduction of a public relations manager as a golden-hearted do-gooder. This we may never have seen before, and it might actually be a more difficult proposal to choke down than Big Willie deflecting 50-caliber shells with a wave of his palm. It’s a cute little conceit though, one of the few inversions that work within a movie that can’t decide if it’s trying to be a humorous drama or a maudlin comedy.

Jason Bateman, as the ad man in question, makes a great everyman—not too tall, not too skinny, not too good looking, and in all the right ways. He’s a perfect surrogate for the average Joe Movie-goer, a comfortably passive lens through which to witness and, perhaps, accept the implausibilities of the action surrounding him onscreen. Bateman very capably creates a perfectly opposed counter to Smith’s staggering hobo-hero. Demonstrably failing in a curious windmill quest to save the world through advertising, and ruefully accepting his own proven ineffectuality, it makes perfect sense that he would recognize and attach himself to true power when it casually wrecks a cargo train to toss him (and his BMW) from the tracks to safety.

If only that locomotive was the only thing to jackknife so disastrously off the rails. As an actor, Bateman’s courageous attempts to ground the story’s perfect storm of contrivance, coincidence and confusion plays as a fascinating parallel to his character’s effort to re-forge and redeem the image of an equally fractured hero.

And the film is plenty fractured. Veering wildly in tone and style, the visuals jump from poorly rendered CGI wide shots of Hancock’s slapsticky escapades in collateral damage to quivering hand-held, gauzy, nose-hair close-ups of the actors’ faces. The music shifts abruptly from occasionally jazzy hip-hop to old-style blues to traditional movie score orchestration (uncomfortably reminiscent of Superman’s famous theme), and with little correlation to the circumstances at hand.

The villain, on top of being an absurdly poor match in brains or brawn for even the most hung-over of heroes, is carelessly spliced into the third act with little or no connection to the bulk of the narrative. The jokes are neither funny nor original. The drama is all predicated on a history left only half explained. The “big twist” is so entirely telegraphed from the first reel that it poses exactly zero surprise when it is revealed and ultimately serves as a point from which the loosely bound raft of a plot comes completely undone, despite the labors of a few beleaguered supporting cast members struggling to keep the crippled vessel afloat.

Hancock, the character, is presented as a disgrace of the tallest order, a paragon of squandered potential whose combination of self-indulgent arrogance and lack of direction hurts an awful lot more than it helps. The most interesting thing about “Hancock” the movie may be how many qualities it shares with its title character.