Bad Academy Awards puns are flying. There's the "Brokeback backlash" ... the little film that "crashed" the party ... the one about "Brokeback Mountain" peaking too early.

While the cowboy love story "Brokeback Mountain" has been established as a solid favorite for the best-picture Oscar when the Academy Awards are announced on Sunday, the ensemble drama "Crash" has an ardent following and some late-season momentum that could make it a surprise winner.

When there's a clear Oscar front-runner, that film almost always goes home with the big trophy. But upsets do happen, and late-surging films have pulled off come-from-behind wins.

Just look back to the 1998 awards season.

"The year of 'Saving Private Ryan,' everybody was certain it was a lock," said film historian Leonard Maltin. "People thought it was a sure thing to win best picture, given the subject matter (D-Day heroics) and the people behind it (Steven Spielberg and Tom Hanks), until the middle of December."

That's when a little film called "Shakespeare in Love" showed up. Oscar voters, along with everyone else, fell in love with it, and while Spielberg won best director, "Shakespeare in Love" grabbed the top prize.

This time around, most signs point to "Brokeback Mountain" — Ang Lee's tale of two rugged Western men (Heath Ledger and Jake Gyllenhaal) in a doomed love affair — as the likely best-picture champ.

Since it debuted in December, "Brokeback Mountain" has swept through awards season, winning best drama at the Golden Globes, snagging honors from top critics groups and earning prizes from guilds representing directors, writers and producers.

The film leads the Oscars with eight nominations, positioning it as the one to beat come March 5.

"Brokeback Mountain" has followed the same release pattern as 2004's Oscar champ, "Million Dollar Baby," starting in a handful of theaters and gradually expanding into wide release and box-office success on the strength of its awards buzz.

But "Crash" grabbed the prize for best overall cast performance at the Screen Actors Guild Awards, surprising some Oscar forecasters. Because of its supposed momentum, "Brokeback Mountain" had been considered a favorite there, too.

After the fact, though, the guild honor made sense for "Crash" — its huge cast and multiple story lines are the virtual definition of an ensemble film. Directed by Paul Haggis, a 2004 Oscar nominee for the screenplay of "Million Dollar Baby," "Crash" features Sandra Bullock, Don Cheadle, Brendan Fraser, Terrence Howard, Thandie Newton and supporting-actor nominee Matt Dillon among dozens of characters whose lives intersect over a chaotic 36-hour stretch in Los Angeles.

"Crash" took an unusual route to the Oscars, emerging out of the 2004 Toronto International Film Festival, where Lionsgate snapped up the film. The movie hit theaters last May and came out on DVD in September, defying conventional wisdom that films released early in the year get forgotten by Oscar time.

Lionsgate took the singular step of providing about 100,000 DVD copies of "Crash" to guild members to ensure that as many as possible had seen the film before voting for the guild's awards. Distributors generally provide about 20,000 to 30,000 DVD copies of awards-contending films to academy members, key critics groups and voters in other Hollywood honors, but this was the first time a group as big as the guild was blanketed with DVDs of a movie.

Tom O'Neil of the awards Web site the envelope.com said the guild win was a sign that "Crash" could be picking up steam as a potential best-picture party-crasher among the Oscars' 5,800 voters.

"Brokeback Mountain" has become a cultural touchstone for Hollywood depictions of gay love affairs, yet the hubbub over the film may be growing stale as Oscar voters cast their final ballots, O'Neil said. And while "Brokeback Mountain" has become a solid box-office success, the gay theme may be off-putting to some Oscar voters, he said.

"Statistically, we know the vast majority of Oscar voters must be straight, if they're at all representative of the general population," O'Neil said. "As much as they admire this movie, it may not feel like it's their movie. If there is homophobia in Hollywood, it could manifest itself there. Or they could just be sick of gay cowboy jokes."

James Schamus — a producer on "Brokeback Mountain" and co-president of Focus Features, which released the film — declined to comment on his movie's front-runner status or the prospects of "Crash" becoming an underdog spoiler.

Schamus, previously involved with such Oscar contenders as "The Pianist" and Lee's "Crouching Tiger, Hidden Dragon," said it's impossible to calculate a movie's awards fate based on such insubstantial notions as "momentum and peaking."

"That allows us to actually pretend we have some clue of what's going on," Schamus said. "It is completely and utterly serendipitous. There's no cause and effect. There's no science to it."

And of course, there are three other worthy films in the best-picture race, the Truman Capote drama "Capote," the Edward R. Murrow tale "Good Night, and Good Luck" and the assassination thriller "Munich."

Along with "Crash," any one of those movies could pull off a win over "Brokeback Mountain," Maltin said.

"Anyone who says that someone is a sure bet for an Oscar is a fool," Maltin said. "There's no such thing as a sure thing, least of all in a five-way vote."