Anyone who makes it into the nation’s top festival already has defeated staggering odds. More than a thousand feature films that don’t have distributors are submitted every year to the festival, with only several dozen making the cut. Of those fortunate few, only a fraction will ever debut in movie theaters. To make the equation even more daunting, the keys to the multiplex are held by but a handful of independent film buyers. At Monday afternoon’s screening of writer-director Jed Weintrob’s provocative “On_Line,” almost all the major independent distributors were present, including representatives from Miramax, Paramount Classics, United Artists and Fox Searchlight. But just half an hour into the film about love, sex and mutual masturbation on the Internet, Weintrob’s Sundance dream took a nightmarish turn. Without a word, the buyers, certain “On_Line” wasn’t for them, walked out nearly as a group, and what had been a packed house within 10 minutes turned half-empty. Standing by the screening room’s entrance, Weintrob watched forlornly as the numerous distributors, averting their eyes, hurried to their SUVs and drove off to another festival screening.

Although sudden death is the unfortunate ending for most Sundance films, a small number enjoy a far better outcome. Surprisingly, the kind of movies that have turned into the festival’s hottest properties in the last couple of years are exactly the works that recently turned off buyers, while those that once fetched the biggest sales—overtly commercial comedies and feel-good dramas—are cold. And that’s good news for an audience eager to see movies just a bit more challenging than “Jimmy Neutron: Boy Genius.”

To understand Sundance’s rapid about-face, some recent history helps. Over the last several years, the festival buyers for the bigger companies like Fox and Miramax usually shunned the sometimes dark dramas disparagingly called “critics’ movies.” Instead, they focused on lightweight crowd-pleasing diversions like the blockbuster “The Full Monty,” which premiered at Sundance in 1997. But the strategy backfired, most notably with Miramax’s expensive and wildly unsuccessful purchases of the comedies “The Castle” and “Happy, Texas” in 1998 and 1999. When those movies tanked, the buyers suddenly weren’t sure what to do, so they sat on their heels. In 2000 at Sundance, no one rushed to buy “You Can Count On Me,” but a wave of positive reviews and awards later turned the film about alienated siblings into one of the year’s most profitable independent releases. Last year at the festival, two difficult movies about the ramifications of murder, “In the Bedroom” and “The Deep End,” attracted modest, but by no measure frantic bidding, selling for $2 million and $2.75 million, respectively. Yet both films were big art-house hits, and “In the Bedroom” is likely a best picture, best actress and best actor Oscar nominee. Who needs “The Full Monty”?

For first-time filmmakers like Karen Moncrieff, that shift couldn’t come at a better time. The 38-year-old former actress used her own money to help finance “Blue Car,” an honest look at two lonely children of divorce, one a self-mutilating 9-year-old and the other her high-school sister, smitten with a supportive English teacher who may not be as honorable as he first appears. With no festival connections, Moncrieff submitted her $400,000 feature on a prayer, and ended up being invited to the dance. “Making a movie and making a good movie requires a series of miracles,” says Moncrieff, whose budget limited her filming to 20 days (about a third the time of a Hollywood feature), and forced her to use Oxnard, Calif., as a substitute for Miami Beach. “The stars really have to align.” They did more than that. After “Blue Car” showed in the festival’s first full day last Friday, the film immediately attracted buyer interest. A troubling movie that likely would have been ignored at Sundance three years ago became the festival’s very first sale, with Miramax snapping up distribution rights for $1.5 million.

What made Miramax’s purchase especially noteworthy was that the studio didn’t wait for the scores of film reviewers attending the festival to render their “Blue Car” verdicts. To sell tickets, weighty, low-budget dramas require more critical support than any genre besides documentaries and foreign-language films. Sundance buyers are constantly checking out not only their competitors but also the reviewers, making sure that if they purchase a movie that can’t possibly be sold in a goofy TV commercial, they at least can count on positive notices. If the critics are not unanimously supportive at the festival, a movie can enter sales limbo, as was the case with “Secretary,” “Gerry” and “Love Liza.” Each film has peculiar challenges. In “Secretary,” James Spader and Maggie Gyllenhaal are involved in a sadistic, sexually demeaning office romance. “Gerry” stars Matt Damon and Casey Affleck in a virtually dialogue-free story about two numbskull hikers who get lost. Paul Walker, whose British company Film Four produced “Gerry,” admitted the backlash against the film (one buyer said the movie was interesting but “not for people”) was hurting its chance for sale, but remained confident a distributor would be willing to gamble on the film. “Love Liza” stars Phillip Seymour Hoffman as the despondent, gasoline-huffing widower of a suicide victim. But Sony Classics believes Hoffman’s “Love Liza” performance is remarkable enough to merit Oscar consideration a year from now, and purchased the film Tuesday for $1.75 million.

And even “On_Line” may ultimately interest a smaller distributor willing to take a chance. Since the film made it this far, it is not yet ready to hang up its modem.