I know Med made last year's final, but I am absolutely going with Thiem. He had a great showing on the HC at the Aus open and he has been in by far the most big matches out of anyone in the field. Feels like his tournament to lose.
For me Zverev , Thiem and Medvedev are all basically co-favourites. Zverev has a great record against Medvedev remember. I am leaning towards Thiem as like razor thin favourite but he could easily lose next round.