Steve Carell - lead of supporting in Foxcatcher?

Andy Serkis - lead or supporting in Dawn of the Planet of the Apes?

How is Serkis supporting when the film is about Caesar?

Anne Hathaway in Interstellar: lead or supporting?
Tye Sheridan in Joe: lead or supporting?

Jaws is about a shark, but Roy Scheider was the lead.

Planet of the Apes (1968) was about apes too, but Heston was the lead. Jason Clarke is the lead in Dawn of the Planet of the Apes because he is the human. He is the one that leads us (the audience) through the picture, not Caesar. The ape pops up when we need him to, but Clarke is the character's story that we are being shown. And more proof that Serkis is supporting: he won a Supporting Actor Saturn Award in 2012 for playing Caesar in Rise of the Planet of the Apes and that film was also "about Caesar" (much more than Dawn is). He was also nominated for an EDA Award as Supporting Actor. And a Critics Choice Award. And an HFCS Award. The San Diego Film Critics Society also nominated him as Best Supporting Actor. And the Satellite Awards. Oh, and the Washington DC Film Critics Awards. All as Supporting Actor. His performance is supporting because he's half acting, half visual effect. It's not a complete performance. It's aided. If he turned into an ape all by himself, then it'd be a full lead performance, but since he cannot and will never be able to do that; he supports the lead cast.

I didn't even think of Pratt until you mentioned him. But I don't classify 'breakthrough' like that. I feel they have to be pretty much unknown in 2013 and then make a name for themselves in 2014 to be classified. At least that's how I will do it. I only heard of Martin and O'Connell this year. I'm having trouble thinking of more, though.

Jamie Foxx was nominated as Best Supporting Actor for Collateral, but that doesn't prove anything because everyone know that he is co-lead.

Well someone has to be the lead and someone has to be the supporting actor, and Jamie Foxx doesn't stand a chance against Tom Cruise, therefore he was supporting.

Whiplash screenplay: adapted or original?

http://www.hitfix.com/in-contention/osc ... by-academy

I tend toward original despite the Academy's decision. I just cannot see a screenplay as ADAPTED because one scene was shot and edited beforehand as a proof of concept for financiers.

Of course, the original/adapted distinction is often hard to pinpoint. A film such as Big Hero 6 is hardly "adapted" in as direct a way as, say, Gone Girl or The Fault in Our Stars.

No, man. A film can have two leads. See Amadeus for instance.