Last weekend's two guild awards threw a whammy into the awards season that no one quite saw coming. While the favourite actors picked up Screen Actors' Guild prizes for their acclaimed performances - Eddie Redmayne in 'The Theory of Everything', Julianne Moore in 'Still Alice', J.K. Simmons in 'Whiplash' and Patricia Arquette in 'Boyhood' - it was the Best Ensemble prize that caused everyone to gasp: it went to 'Birdman'.

'Birdman' won the Best Ensemble cast award at the Screen Actors' Guild awards
'Birdman' won the Best Ensemble cast award at the Screen Actors' Guild awards 

The night before, at the Producers Guild of America awards, 'Birdman' had also won the night's top prize. Until now, 'Birdman' has only been seen as one of many to be gunning for the top spot. Now, things have changed: it's the front-runner; the film to beat on Oscar night.

More: Read the review for 'Birdman'

Awards-season analysts have a lot of theories about what has changed. Mainly, they point to 'Birdman''s knowing subject matter: it's a movie about Hollywood itself, something that also worked for recent Best Pictures like 'The Artist' and 'Argo'. By contrast, critics have fallen hard for Richard Linklater's 'Boyhood', acclaimed as the film of a generation, a work of artistic achievement that Hollywood has never done before and never will again.

Watch the trailer for 'Birdman' here:

There are still two big predecessors to go before all attention settles on Hollywood Boulevard for Oscar night on 22nd February. Next weekend sees both the Director's Guild awards in Los Angeles and the Baftas in London. Until then, the race is anyone's.

More: 'Birdman' Wins SAG Best Picture, Blows Oscars Race Wide Open