Positioned almost a month away from the Academy Awards ceremony, the Screen Actors’ Guild Awards are frequently something of a buzzkill in the Oscar race — not because they don’t make for a perfectly entertaining evening in themselves, but because they have a nasty habit of sealing up the competition in a number of categories, making life rather dull for attentive awards-watchers.

A certain degree of overlap with the Academy membership makes their routine foreshadowing of the acting Oscar winners — in the 17-year history of the awards, nearly 70% of the performances honored by SAG went on to take the big prize — inevitable, though since the awards calendar was reshuffled a few years ago, they tend to answer some questions in the race a bit too early. With this year’s acting races already showing little wiggle room, don’t count on the Guild to open things up.

Last year, for the first time ever, the SAG results were duplicated entirely by the Academy, with even Best Performance by a Cast, the group’s top prize, going the way of the eventual Best Picture winner, “The King’s Speech.” The year before, those two awards were split between “Inglourious Basterds” and “The Hurt Locker,” but the Guild and the Academy nonetheless agreed on all four performance winners; the level of convergence between the awards is as high as ever.

Let’s take a look at each category individually, bearing in mind that by predicting these, we may as well be predicting the Oscars too.

BEST SUPPORTING ACTOR

Four of the actors nominated by SAG — Christopher Plummer, Kenneth Branagh, Nick Nolte and Jonah Hill — found their way into the Academy lineup; “J. Edgar” star Armie Hammer always looked a bit odd in this field, and not just because the makeup team were informed that Clyde Tolson suffered late-breaking progeria. On paper, you’d expect a tight contest between three esteemed veteran actors with no SAG Awards or Oscars between them (no, not you, Jonah), but in reality, Plummer has had this race licked since “Beginners” opened in the summer. And rightly so: Branagh’s amusing but thin-crust impression of Laurence Olivier in “My Week With Marilyn” and Nolte’s affecting but underdrawn grizzly-dad act in the little-seen “Warrior” can’t match Plummer’s late-blooming gay widower for nuance and grace, while neither is owed quite as big a debt by the industry as the 82 year-old Canadian.

Will and should win: Christopher Plummer, “Beginners”  

BEST SUPPORTING ACTRESS

Remember how last year’s Best Supporting Actress race seemed so open and malleable until Melissa Leo duly picked up the BFCA, Golden Globe and SAG Award in swift succession — and not even her own iffy PR could make it look like a contest again? That, I feel, is where we are this year: I sensed opportunities at one point for 2011’s it-girl Jessica Chastain or 1927’s it-girl Bérénice Bejo to stake a claim on the Oscar, but BFCA and Globe winner Octavia Spencer is proving mighty difficult to get around: she has the tangiest storyline in a film a lot of people love, and there’s palpable affection in the industry for a hard-working character actress finally enjoying her moment in the sun. You can try making a case for Bejo winning on a tide of goodwill for “The Artist,” or “Bridesmaids” breakout and sitcom star Melissa McCarthy — the second nominee in this category, oddly enough, for whom shit is an integral plot point — picking up votes from SAG’s vast TV contingent, but I think we know how this is going.

Will win: Octavia Spencer, “The Help”

Should win: Jessica Chastain, “The Help”

BEST ACTOR

Whether it’s a sign of genuine affection for “The Descendants,” or simply for an industry-leading star who’s had a big year before and behind the camera, George Clooney has comfortably worn a frontrunner’s groove into this race — despite his performance not being visibly more spectacular than those of his competitors, his tally of critics’ awards being lower than some of them, and hardly anyone in the industry deeming him under-rewarded. He has an Oscar, after all, which is one more than Brad Pitt, doing some of the warmest, most textured work of his career in “Moneyball,” can claim. What Clooney doesn’t have, as it happens, is a SAG Award, and his fellow actors are unlikely to resist the opportunity to furnish his mantel with one of those. If Pitt is to activate an Oscar narrative that superficially makes more sense than Clooney’s this year, now’s the time, but I sense Jean Dujardin, irresistible in “The Artist” and a natural on the publicity trail, is the likelier spoiler. Demián Bichir and Leonardo DiCaprio, meanwhile, should enjoy the canapés.  

Will win: George Clooney, “The Descendants” 

Should win: Jean Dujardin, “The Artist”

BEST ACTRESS

This is the acting race that currently feels most like just that: a race. After winning the BFCA Award, Viola Davis seemed to make good on her long-presumed frontrunner status, only for Meryl Streep to nab the Golden Globe, giving the actress at least the appearance of having caught up — though the HFPA are such avowed Streepoholics that it’s hard to say what that win means in the wider scheme of things. There will no doubt be much peer admiration for Streep’s impressive Maggie mimicry in “The Iron Lady” — but Davis, the kind of well-liked, long-serving character actress SAG loves rewarding, giving a heart-tugging performance in a film they clearly adore, would appear to have the edge here. Michelle Williams looked more of a threat a month ago, when she was racking up the critics’ awards; Glenn Close looked less of a threat many months ago, when people saw her film. What a shame the finest, most fragile turn here is the only one not up for an Oscar.  

Will win: Viola Davis, “The Help”

Should win: Tilda Swinton, “We Need to Talk About Kevin”

BEST CAST

Accepted wisdom is that this is SAG’s Best Picture award is disguise, though it’s worth noting that they don’t always use it in a cravenly predictive capacity: though overwhelming frontrunner momentum can sometimes hand the win to a film like “Slumdog Millionaire,” despite it not being especially actor-focused, they’ll often spring for an Oscar outlier just because they really do like the cast: “Inglourious Bastards,” “Sideways,” “Gosford Park” and “The Full Monty” all won the prize, and didn’t look any more like Best Picture threats because of it. 

This is looking like one of those years to me: though it’s possible that the general sense of goodwill for the film, plus the presence of several familiar American faces alongside the less widely recognizable French leads, could swing it the way of “The Artist,” I think this will be the night top nominee “The Help” — no longer a serious Best Picture contender after a surprisingly poor Academy showing — gets to shine, particularly with a group that leans more commercial and more middlebrow than most. Meanwhile, I wouldn’t be entirely stunned to see the TV contingent pull out a wild-card win for the frisky female ensemble of “Bridesmaids”; an ensemble win for either “Midnight in Paris” or “The Descendants,” despite their higher status in the race, would be more of an upset, for my money.

Will win: “The Help”

Should win: “Bridesmaids” 

What are your predictions and/or wishes for Sunday’s awards? Share them in the comments. 

For more views on movies, awards season and other pursuits, follow @GuyLodge on Twitter. 

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