The Golden Globe Awards are notoriously unpredictable, and this year looks to be shaping up as especially difficult to forecast. Most categories do not have an obvious frontrunner, and with a take-no-prisoners host like Ricky Gervais guiding the show, anything could happen on Sunday night.

With that in mind, here are five things to keep your eye on during the 73rd annual Golden Globes.

Ricky Gervais

Good, bad or meh, the host is always a topic of conversation at an awards show like the Golden Globes. This year's host promises to be controversial, if nothing else, with British comedian Ricky Gervais back in the role he was banished from in 2012.

Gervais hosted the Globes from 2010-2012, during which time he took comedic shots at just about everybody he could. Gervais mocked Mel Gibson and Charlie Sheen for their drinking issues, guffawed at the flop that was Johnny Depp's "The Tourist," cracked a penis joke about Hugh Hefner and openly declared the Golden Globes the second-best awards show on television. "The Golden Globes are to the Oscars what Kim Kardashian is to Kate Middleton," he said on one occasion. "A bit louder, a bit trashier, a bit drunker and more easily bought."

Gervais was canned as host after 2012, to be replaced by Tina Fey and Amy Poehler. But after three years of the "SNL" gal-pals, the Globes decided to go back to Gervais as host.

Gervais recently told talk show host Conan O'Brien that he returned to the Globes because organizers said he could "say what you want again."

"I said, 'OK, I'm in," he told Conan.

Oscars crapshoot

The Golden Globes can offer a bit of a preview to the Oscars in February, but the two presentations often diverge when it comes to the big awards. That's due, in part, to their membership.

The Oscars are selected by the Academy of Motion Picture Arts and Sciences, which is made up of actors and movie industry professionals, largely based in the United States. The Globes, however, are voted on by the Hollywood Foreign Press Association – a collection of journalists and photographers who report on Hollywood for organizations based outside the United States.

Those two groups have made some wildly different selections over the years. For instance, the Globes and the Oscars have selected different winners for Best Director six out of the last 10 years, and have chosen different Best Pictures five out of the last 10 years.

However, the two organizations tend to be more in-step when it comes to awards for best supporting actor, best actor and best actress, with winners in the Globe categories going on to win nine out of the last 10 years.

Comedy, Musical or Mars movie

Did you know "The Martian" is a comedy?

At least, it's being categorized as one by the Hollywood Foreign Press Association, meaning it will be on the Musical or Comedy ballot for Best Picture and Best Actor.

There are definitely some comedic moments in director Ridley Scott's film, but it's a big stretch to label it a comedy. The movie is about an astronaut (Matt Damon), who must struggle to survive after being stranded on the planet Mars. There isn't even a volleyball to keep him company, a la "Cast Away."

Nevertheless, "The Martian" will be taking on the likes of "Joy," "Spy," "Trainwreck" and "The Big Short," instead of going up against "Mad Max: Fury Road" and "The Revenant" in the Drama category.

Matt Damon will also be vying for Best Actor in a Motion Picture in the Musical or Comedy category, taking on Al Pacino ("Danny Collins"), Mark Ruffalo ("Infinitely Polar Bear"), and "The Big Short" co-leads Christian Bale and Steve Carell.

If things shake out right for "The Martian," the joke might be on the actual comedies in this category.

Unexpected (and sometimes drunken) moments

If Gervais is right about anything, it's that the booze flows more freely at the Golden Globes than it does at the Oscars. Actors sit at tables and have access to drink service, meaning the speeches tend to become more and more unintelligible as the night goes on.

All that alcohol has generated a number of ill-advised, awkward, off-the-cuff and genuinely baffling moments at the Globes over the years, and this year is likely to be no different.

In 2014, for instance, Diane Keaton sang a bizarre lullaby on stage, after accepting the Cecil B. DeMille Award on Woody Allen's behalf. "Make new friends but keep the old," she (sort of) sang. "One is silver but the other is gold."

Also that year, Emma Thompson took the stage with her high-heeled shoes in one hand and a martini glass in the other. "I just want you to know – this red? It's my blood," she said, holding up her shoes. She then slurred through a few more lines about the award she was there to present, before tossing her shoes over her shoulder and accepting an envelope with the winner's name on it.

A year earlier, Jodie Foster used her Cecil B. DeMille win to (sort of) address rumours about her sexuality, in a hesitant, evasive speech. "I just have a sudden urge to say something that I've never been able to really air in public," she said on stage. Foster then apologized that there would not be a "big coming out speech tonight," before talking about her female partner and the value of privacy.

And with all the drinks on hand, there's always the possibility a star will miss her moment for a bathroom break.

That's what happened in 2001, when Hugh Grant announced Renee Zellweger as the winner of Best Actress, while the actress was away from her seat. "Where is she?" Grant said. "She's under the table? Renee is drunk, ladies and gentlemen … She's disappeared. She's in the bathroom. OK, what do we do?"

Zellweger then returned from her visit to the bathroom, and was forced to take the stage immediately.

Mel Gibson

Mel Gibson's presence at the Golden Globes will no doubt have some raising a skeptical eyebrow, after the actor's very public disgrace in 2006. Gibson's career tanked that year after he was recorded delivering a drunken, anti-Semitic tirade to a police officer during a traffic stop.

Now, after nine years and a handful of bit parts in films, Gibson has been invited to present an award at the Globes.

Expect Ricky Gervais to taunt him mercilessly, if nothing else. Gervais mocked Gibson's drinking back in 2011, and has already targeted him for another joke or two this year. "Mel Gibson is presenting an award at the Golden Globes," Gervais recently tweeted. "Thank you Jesus."