The Academy Awards are the most wagered-upon nonsporting event in the world, so it’s safe to say that more than a few fortunes have probably been lost when the Academy ventures away from the expected script. But few prizes have rattled the oddsmakers more consistently than the supporting categories, where unknowns can come out of nowhere to either establish a lasting career or flame out dramatically, downplayed leading men find their way and grizzled veterans finally get their dues, and even Mira Sorvino can pick up an acting honor.At first glance, the supporting actress category seems the most unwieldy of the two, having given us Oscar’s youngest acting winner (10-year-old Tatum O’Neal in “Paper Moon”), oldest acting nominee (Gloria Stuart, 87 at the time of her “Titanic” nomination) and the two shortest Oscar-winning performances (take a bathroom break and you’ll miss Beatrice Straight in “Network” and Judi Dench in “Shakespeare in Love”). In recent years, however, it helps to have the Maxim demographic on your side. “It’s become rather axiomatic to say that in the supporting actress category they tend to go for ingenues or hot women in general, and I think it’s a recent development,” says Damien Bona, Oscar historian and author of “Inside Oscar.” “Over the last several years, when you have Catherine Zeta-Jones, Rachel Weisz, Renee Zellweger, Jennifer Connelly, Kim Basinger and Angelina Jolie, it’s happened enough that it’s fair to call it a trend.” Bona notes that this is an about-face from the early history of the award, when young starlets were rarely seen on the ballot. “Over the first 50 years or so, the category was dominated by middle-aged or older character actresses,” Bona observes. Indeed, while the last decade’s supporting actress winners constitute a veritable who’s-who of A-list actresses, mentioning the names of past winners such as Lila Kedrova, Peggy Ashcroft and Mercedes Ruehl would likely draw blank stares from anyone raised on TMZ (then again, most things would). Bona sees this as a reflection of the Academy’s increasingly more practical approach. “By going with young actresses, it’s a way of promoting the future of the industry. They think in a much more business-oriented context than they used to,” he says. Then again, a number of young actresses have parlayed an early supporting honor into a long career, which should give some hope to last year’s winner, Jennifer Hudson, who won for her first film role, in “Dreamgirls.” This puts her in such good company as Anna Paquin, Lee Grant and Goldie Hawn (who won for her first speaking role in 1969′s “Cactus Flower,” although technically, she did manage a few giggles in her turn as “Giggly Girl” in the previous year’s “The One and Only, Genuine, Original Family Band”). And, going way back, Gale Sondergaard won the first ever supporting actress Oscar in 1936 for her bigscreen debut, “Anthony Adverse.” As for the supporting actor category, the Academy’s tastes are a bit harder to discern. They’ve certainly shown a sentimental fondness for beloved older veterans (Alan Arkin, Morgan Freeman, Michael Caine, Martin Landau, Jack Palance) as well as a tendency to honor up-and-comers, or at least those who seem to be headed in that direction (Kevin Spacey, Cuba Gooding Jr.). But Bona also sees a growing tendency to honor lead actors in the supporting category, which creates problems of its own. “It’s become a place where stars go slumming,” he observes. “Tim Robbins, George Clooney, Jack Nicholson, Gene Hackman — these are all bona fide leading men. I think it’s unfortunate. It’s great when Chris Cooper or Jim Broadbent win, because they’re exactly the kind of actors for whom this award was designed.” In the old days, “leading actors would be mortified if they were put into the supporting category,” Bona says. “During the early years, the supporting categories were almost exclusively the province of character actors. In 1943 there was controversy when Paulette Goddard was nominated for supporting actress for ‘So Proudly We Hail,’ and people took umbrage that an actual movie star was slumming in the supporting category. Likewise with Anne Baxter, who was already a young movie star when she won for ‘The Razor’s Edge.’” Of course, in recent years these already nebulous lines between lead and supporting parts have blurred even further, with arguable lead roles relegated to the supporting categories for no apparent reason other than increasing their chances of winning. But perhaps that’s fitting, as the winners of Oscar’s most unpredictable categories often tend to be quite unpredictable themselves — from Jack (“I crap bigger than Billy Crystal”) Palance’s one-handed push-ups to “Hannah and Her Sisters” winner Michael Caine ditching the ceremony to finish filming his masterwork “Jaws: The Revenge.” And then of course, there’s Vanessa (“Zionist thugs”) Redgrave, who is in contention again this year for her supporting work in “Atonement,” poised to defy the oddsmakers and the tastemakers once again.