Will Smith opening a movie used to guarantee success — is that still true?

“Concussion” is supposed to be the movie that shows us Will Smith is a Serious Actor.

After helming a series of films that either weren't memorable (“Men in Black 3”), underperformed (“Focus”) or simply flopped (“After Earth”), Smith, 47, is in the position of trying to convince us he's capable of being more than just Mike Lowrey, Hitch and Hancock.

In “Concussion,” Smith plays Bennet Omalu, the Nigerian doctor credited with discovering Chronic Traumatic Encephalopathy, the brain disease that drove former NFL players such as Dave Duerson, Ray Easterling and Junior Seau to commit suicide. Its effects were so torturous to former Pittsburgh Steelers center Mike Webster that he used to Tase himself until he passed out just to get some sleep.

The NFL, which tried for years to silence his findings, is not exactly a big fan of Omalu's work.

Omalu is shorter and slightly broader than Smith. His skin is darker, and he has a very pronounced brow bone that affixes his face in a permastate of semi-seriousness. There's a musicality in the delivery of his speech. He has a quiet, earnest sort of charm.

Even when speaking about profound ideas, as he did in interviews for the PBS Frontline documentary “League of Denial,” Omalu is matter-of-fact, as if he's stating the obvious.

“I rather want to be told the truth, and deal with the truth, than be wallowing in ignorance and darkness and lies,” Omalu says at one point, as he's explaining his initial surprise at the NFL's response to his findings.

Smith, on the other hand, made us fall in love with him — and became, at one time, the biggest movie star in the world — by being the human equivalent of a puppy. He's tall and handsome and goofy and eager to please. There's an openness about his physical presence that makes him a fantastic talk show guest when he's promoting movies. He has an energy and confidence that is irrepressible.

Playing Omalu then, was meant to showcase Smith's range. And so Smith spends almost the entirety of “Concussion” with his brow furrowed and his jaw clenched. A series of subtle changes helped to make Smith look less like himself. Judy Murdock, the film's makeup artist, pinned back Smith's ears with the help of a small prosthetic. She used a process she calls “Obama aging” to emphasize the stress of Omalu's job. Barber Pierce Austin made changes to Smith's hairline, and the addition of gray around his temples adds maturity.

Much of “Concussion” is a dreary, under-saturated affair, the better to reflect the grimness and solemnity of its subject. By adjusting the makeup in concert with the lighting direction, Murdock was able to “restructure” Smith's face and make his eyes appear a little more deep-set like Omalu's.

On screen, Smith labors to make himself smaller, stiffer and shyer to reflect a character who is more comfortable speaking to dead people on a pathologist's table than live ones trying to dance with him in a nightclub.

When the trailers for “Concussion” debuted, the first critique of Smith's take on Omalu was that he had failed to master a Nigerian accent. Smith's accent does drop occasionally through the film, particularly in areas where he's required to raise his voice. Is it a typical Nigerian accent? No. Is it closer to the way Omalu's own voice has been filtered through years of study in London and the United States? A bit.

The question now is whether Smith's turn will be enough to net him awards consideration during a season that's up in the air and thick with contenders. For at least the past week and a half, Leonardo DiCaprio has assumed the position of favorite to win the Academy Award for best actor after so brutally tormenting himself for “The Revenant.” Outside of Hollywood though, Smith and “Concussion” are perched behind a bully pulpit, calling for better ethics.

“Tell the truth!” Smith earnestly demands through clenched teeth as Omalu.

Smith made us laugh as the Fresh Prince and alternately cringe and whoop as we watched his “Bad Boys” escapades. Can he and the glare of a big-budget movie put the NFL on notice and make us question our national obsession with football? Agent Leigh Steinberg, whose own ethical crisis over concussions in the 1980s was eventually immortalized by Tom Cruise in “Jerry Maguire,” thinks so.

“I think the movie will play a vital role in awareness and re-engage the public in this discussion in the same way that Junior Seau's death or Dave Duerson's death or the lawsuit did,” Steinberg said.

“I think the fact that it's a major motion picture built around the story of a person, as opposed to being a straight-out preachy screed, and it stars as popular a movie star as there is in the country, who's very, very accessible to people — I mean a very moviegoer friendly star — makes the story much more accessible to people than watching a documentary, than reading a story about it,” Steinberg continued.

“It brings the story home in a way that has the potential to reach many more people than the documentary ‘League of Denial' or (who) read a news story on concussions and turn away.”