Steve Carell, "Foxcatcher"
Role: Wrestling-obsessed multimillionaire John du Pont.
In his favor: The comic actor flexes his dramatic muscles as a selfish oddball with a penchant for firearms. Weight gain, beaked nose. (Other nominations: G/S/B)
Then again: His against-type turn is moving, but no equal to "The 40-Year-Old Virgin." His only real relationship in the film is with his ego. Is he a leading actor here or supporting?

Bradley Cooper, "American Sniper"
Role: Chris Kyle, decorated Navy SEAL sharpshooter.
In his favor: Playing a strong, silent but tortured soldier is a major switch for an actor whose resume tends toward the comic and romantic. Cooper put on a huge amount of muscle, the kind of physical transformation that voters love.
Then again: No nominations from the Golden Globes, SAG or BAFTA, which could foreshadow an Oscar loss.

Benedict Cumberbatch, "The Imitation Game"
Role: Alan Turing, England's wrongly dishonored World War II code-smasher.
In his favor: He mixes arid humor, captivating strangeness and touches of arrogance in a well-calibrated portrait of an emotionally clueless, gay, misfit math prodigy. (G/S/B)
Then again: The film doesn't crack the code of how Turing's closeted sexuality led to his bleak final fate.

Michael Keaton, "Birdman"
Role: Fallen superhero icon Riggan Thompson, seeking a Broadway comeback.
In his favor: He's arch, dizzyingly funny, vulnerable, ingenious, totally killing it in a role that seems like Keaton's own life story. (G/S/B; Globe winner)
Then again: The strange, dreamlike script can't make up its mind whether the world is nuts or Riggan has lost his marbles. Oscar voters like laughs but need coherence.

Eddie Redmayne, "The Theory of Everything"
Role: Theoretical physicist and cosmologist Stephen Hawking.
In his favor: It's a genius portrait of a genius. Redmayne is equally good when he can't move or speak. Only Buster Keaton expresses himself with less facial mobility. (G/S/B; Globe winner)
Then again: Daniel Day-Lewis won for playing a brilliant mind trapped in an imperfect body in "My Left Foot," a much richer film.
ROBBED

David Oyelowo, "Selma"
Role: Rev. Martin Luther King Jr.
In his favor: Less a performance than a rebirth of a national hero. The emotions, actions, appearance, articulation and even character flaws are remarkably effective.
Then again: The film's jabs at former President Lyndon Johnson triggered political criticism that could sink the film among academy voters. Oyelowo got a Globe nomination but not SAG or BAFTA.