Tomic in 4 is most likely outcome. Groth improoved his baseline and return game from last year, so might win 1 tie-break or 1 set with break vs Tomic, who will probably struggle to break Groth his return is pretty bad, anyway from the baseline Tomic will win more rallies - but not significantly more, how i said Groth improoved, on serve it doesn´t matter if Groth hits 30 aces and bombs 220-235kph all the time if Tomic will win his service points with unreturnable serves or easy points like taking Groth outwide with slice serve just to hit easy FH-BH to open court, so Groth might have similar 1st serve points won % like Tomic, but on 2nd serve Tomic should win more + his FS% can be higher and in tie-breaks he is the one who should be more comfortable- something like 6-3,6-7,7-6,6-4 for Tomic