In recent years there has been some correlation between Hamilton's off-track activities and his performance on-track. He needs to be a happy bunny, and a focused one at that, to beat Rosberg. But he can do it. Hamilton wasn't completely satisfied with the brakes in the W04, it has to be seen how that's settled in the WO5. I think these will be the main influences. Rosberg just seems solid to me, never distracted from his job and hardly ever far in the wrong direction. It's still a fantastic combo and the stakes for them are higher than ever at Mercedes, so it's going to be very interesting how this fight develops in the first couple of races, especially if it's going to decide the lead in the championship, which looks likely to be occupied by either one of them.