Back in September, it was going to be "Silver Linings Playbook."

Then it was "Argo."

Then "Les Miserables." "Zero Dark Thirty" picked up some steam. "Lincoln" got raves.

Then back to "Les Miz." Over to "Lincoln." And, finally, the buzz settled on "Argo."

This year's Oscar race has been anything but predictable.

As festival chatter has given way to box office tallies, critics' honors and guild awards, the perceived leaders for best picture have changed almost as often as the country's top-ranked college basketball team. The Academy of Motion Picture Arts and Sciences further muddied matters when it failed to nominate the directors of four Best Picture nominees -- "Argo," "Zero Dark Thirty," "Les Miserables" and "Django Unchained" -- for Best Director.

Bad for the conventional wisdom. Good for competition.

"I love all the suspense this year," said Oscar watcher Tom O'Neil, who runs the GoldDerby.com awards blog. "There are a lot of precedents being set."

For example, he observes, usually the film with the most nominations is the front-runner for best picture. This year, the most-nominated film is Steven Spielberg's "Lincoln," which earned 12 nods. But the movie that's shown the most staying power at the various awards ceremonies since then -- including the Golden Globes, SAG Awards and the Producers Guild -- has been Ben Affleck's "Argo," making the latter film the front-runner for the big prize Sunday night. "Argo" is up for seven Oscars.

Moreover, Affleck's picture has dominated despite being snubbed by the academy in several categories, most notably best director. (In fact, among the Big Six categories of picture, director, actor, actress, supporting actor and supporting actress, "Argo" has just two nominations, three fewer than "Lincoln," despite a top-notch cast.) In the entire history of the Oscars, just three films have won Best Picture without a directing nomination. The most recent was 1989's "Driving Miss Daisy," which won the top prize despite director Bruce Beresford getting shut out.

Unlike Beresford, however, Affleck received the support of his peers at the Directors Guild of America, which awarded him its top prize a few weeks ago; Beresford didn't even make the DGA cut in 1989.

Is the rank-and-file trying to send the academy a message?

O'Neil believes they are.

Years ago, he points out, a situation like Affleck's Oscar snub would have been noted and then forgotten in the face of a much-nominated film such as "Lincoln." Today, with social media and blogs constantly debating the Oscars' merit, the argument isn't over until PricewaterhouseCoopers finishes tallying the votes.

"That's evidence of how different the Oscars are today," he said.

In addition, the DGA award is about the many over the few: The DGA is voted on by more than 14,000 members of the directors' guild -- a group that includes assistants, TV specialists and other forms of helmers -- while the Oscar nominees for Best Director were selected by the roughly 370 members of the academy's directors' branch, a more homogenous group, said O'Neil.

Clayton Davis, who oversees AwardsCircuit.com, has another theory: that "Argo" is everybody's alternative. Given the way the Oscars are tallied, with voters ranking their picks from favorite to least favorite, a film with a lot of twos and threes will do better than a film that some people love and others loathe.

"You'll find your haters for 'Lincoln,' you'll find your haters for 'Zero Dark Thirty,' you'll find your haters for 'Les Miz.' But everybody, for the most part, at least says 'Argo' was good," he said. "So in a preferential balloting system 'Argo's' not likely to have a lot of No. 9 votes. And in a preferential balloting system, two, three and four can easily make up the winner."

Lifetime achievements and new faces

This year, at least, almost all the Best Picture nominees have a rooting interest. As opposed to recent years, when many nominees struggled to crack even $50 million domestically, this time all but three of the nine Best Picture films -- "Beasts of the Southern Wild," "Amour" and "Zero Dark Thirty" -- have topped $100 million at the North American box office. Some have established financial benchmarks: "Django Unchained" is Quentin Tarantino's highest-grossing film ever, and "Silver Linings Playbook" is tops among David O. Russell's films.

And though the Oscars are Hollywood-centric, the global market is always in studios' thoughts. In that respect, "Life of Pi" has been a juggernaut, making almost $600 million worldwide since its release.

"Life of Pi," in fact, may sneak into the winner's circle if the "Argo" bandwagon slows. One academy voter interviewed by CNN said "Pi," directed by Ang Lee, was his favorite film among the nominees; "Argo" didn't make his top three. (Neither did "Lincoln," for that matter.) Davis adds that anybody voting for Spielberg will likely vote for "Lincoln," and because "Lincoln's" momentum has halted he suspects Spielberg will lose Best Director to Lee or Russell. Lee, whose film was a special-effects marvel, may have the many members of the technical branches behind him.

"If Spielberg wins director, he's going to have three director wins, but only one of his films ('Schindler's List') will have won Best Picture in his career," he said. "That would be a little crazy. So I think Russell and Ang Lee are coming up strong."

O'Neil agrees. "Life of Pi" also has the second-most Oscar nominations this year, it received 11, and "its back story is extraordinary," since Yann Martel's best-selling 2001 novel was long considered unfilmable, he said.

Best Picture isn't the only category without a shoo-in. In fact, with the exception of Best Actor, which has been Daniel Day-Lewis' race to lose since the "Lincoln" trailers first hit the Web, the other contests are still anybody's guess.