Often times, the acting races at the Academy Awards are fairly cut and dry. By the time we get to the Oscar ceremony, it is usually pretty clear which actor is the frontrunner. A lot of this certainty lies in the Screen Actors Guild awards, whose winners often go on to win the Oscar. This is because the acting branch of the Academy is the largest, and the overlap between those voters and the SAG voters is enough to see a general pattern of voting.

This is not to say that upsets are impossible. An upset happened as recent as last year in this very category. So let’s look at who could possibly unseat the frontrunner this year.

The Nominees:

• Charlize Theron – Bombshell
• Cynthia Erivo – Harriet
• Renee Zellweger – Judy
• Saoirse Ronan – Little Women
• Scarlett Johansson – Marriage Story

Will Win: Renee Zellweger

Could Win: Scarlett Johansson

Dark Horse: Charlize Theron

Last year at this time, Glenn Close was the (more or less) runaway favorite to win Best Actress. She was sweeping throughout awards season as the lead in The Wife (aside from the BAFTA, which went to Olivia Colman). Then, on Oscar night, she walked away as the most nominated actress without an Oscar win.

The same could happen to Renee Zellweger this season. The films are similar. The Wife and Judy are both small films with central performances from their female leads. They both came out mid-year to meager amounts of buzz. Judy has a slightly more present Oscar campaign than The Wife (it also received a Best Makeup and Hairstyling nomination), but it is otherwise a fairly forgotten film.

A SAG loss for Zellweger could open this race back up in an instant. The other nominees are all big, strong performances. I don’t really think that is going to happen, though.

The upset potential in the next strongest performance, that of Scarlett Johansson in Marriage Story, may be squandered by her double nomination. Her nomination for both Marriage Story and Jojo Rabbit shows that the acting branch appreciates her work, but the double nomination could, in a manner of speaking, split the vote. I don’t think many ballots would vote her number one in both categories. Voters who maybe like Jojo Rabbit better could sink Johansson lower in the Best Actress ballot.

Bombshell and Harriet didn’t make a huge splash on awards season. The two lead performances could potentially win in a less-crowded field, but I don’t think they stand much of a chance against Zellweger and Johansson. As for Saoirse Ronan, it is a notable performance in an ensemble picture. Given Little Women missed out on some key nominations, dropping its overall stock a bit, and Ronan’s performance is more understated than her co-star and fellow nominee Florence Pugh’s, it seems like a steep hill to climb for Ronan to win. And this is without mentioning her lack of representation at the SAG Awards.