Even before the 89th Academy Awards get under way, there are rock solid certainties about what will take place.

* Let's hope Viola Davis has written a good speech because, of all the nominees in all the categories, she is the biggest certainty to win for her emotional performance as the resilient wife of a former star baseballer in Fences.

While in the wrong category – she's clearly the female lead in the film – Davis has won all the key lead-up awards and has much more time on screen than any of other nominee. So in a year that voters are expected to address the #OscarsSoWhite controversies of the past two years, Davis is a cert.

Sorry, no second Oscar for Nicole Kidman (Lion) this year.

* La La Land will win best cinematography, production design and score and very likely a shelf full of other Oscars from its record-tying 14 nominations. Could even be eight to 10.

But while the Ryan Gosling-Emma Stone musical has been hot favourite for best picture for months, it's no take-it-to-the-bank sure thing.

Firstly, there's the backlash from the general audience if not critics. Then there's the impassioned support for Moonlight, Manchester By The Sea and Hidden Figures. And we are yet to see the impact of last year's membership overhaul to make the Academy more diverse. Who's to say the #OscarsSoWhite factor won't carry Moonlight to best picture?

Last year, The Revenant was favourite when it was beaten by Spotlight. And history shows that strange things can happen at the Oscars, like way back when Ordinary People beat Raging Bull to win best picture and Kramer vs Kramer beat Apocalypse Now.

* Is Casey Affleck guaranteed to win best actor? Not really.

Just like La La Land, he has been raging favourite for months for playing an emotionally damaged janitor in Manchester By The Sea. But the resurfacing of allegations that he sexually harassed women while making the 2010 film I'm Not There seems to have damaged his chances.

According to the 30 Oscar experts polled by awards web site Gold Derby, Denzel Washington (Fences) has taken over favouritism. With Davis winning best supporting actress and Mahershala Ali (Moonlight) favourite to win best supporting actor, it could be a landmark year for African-American actors.

* While it might not start with host Jimmy Kimmel's opening monologue, these will be a politically charged Oscars.

Already George Clooney has taken at shot at President Donald Trump at France's Cesar Awards, saying: "Love trumps hate. Courage trumps fear. And right always trumps wrong." In Los Angeles, Jodie Foster has called for more activism at a rally organised by a talent agency, saying: "All the colours in the identity rainbow, this is our time to resist. It is the time to show up and demand answers."

And the directors of all five nominations for best foreign-language film, including Australians Bentley Dean and Martin Butler from Tanna, have issued a joint statement decrying "the climate of fanaticism and nationalism" and saying they want the award, whoever wins, to stand "as a symbol of the unity between nations and the freedom of the arts".

One nominee, Iranian director Asghar Farhadi, is boycotting the Oscars in protest at the proposed travel ban on seven largely Muslim nations.

It might be too much to hope that Alec Baldwin will appear as Donald Trump but it's not a stretch to think the President will tweet a reaction to the Oscars at some stage.

* These awards will be emotional. How could they not be after the death of such beloved stars as Alan Rickman, Prince, Debbie Reynolds, Carrie Fisher and Gene Wilder, along with young Anton Yelchin?

While one actual nominee is dead, he will not win because ...

* Fences is up for best adapted screenplay and, judging from the film, the late August Wilson barely adapted his own stage play for the screen.

It's so talky it's like being trapped in a lift with Denzel Washington on fast forward and so stagy the most interesting things happen off camera. For all its blazing concern with black struggle and identity, it's a case study in how not to adapt a play into a fully realised film.

* While there are a record 14 Australian nominations, there won't be anything like the six wins like there was for Mad Max: Fury Road last year. The country's best chances are Hacksaw Ridge in the sound categories and Lion in best adapted screenplay, cinematography and supporting actor.

* While Stephen Colbert, Seth Meyers or John Oliver would bring more edge – sadly the Oscars will never be ready for Ricky Gervais – Kimmel will be funny.

But he has been wisely playing down expectations. "I made a decision to try to enjoy the process and be optimistic," he told Variety. "That said, my subconscious still tells me it's going to be a disaster."

For the sake of the hours of Oscars watching ahead of us, let's hope it's a livewire, fascinating awards full of memorable moments. And if it's not, let's hope for an entertaining disaster.