On paper it looks like another Austin race that is Lewis Hamilton's to lose, but the closer you look at the real picture from free practice, the clearer it becomes that even Mercedes doesn't truly know where it stands yet.
It's fatuous to talk about the chances of Sebastian Vettel striking back in the title race given it's surely now a question of when, not if, Lewis Hamilton clinches the crown. Besides, the Mercedes driver was fastest on Friday, so it's going to be another easy win for Hamilton, right?
Well, perhaps not, because there was a hidden battle going on under the surface of a mysterious day of practice for the United States Grand Prix. Anyone who thinks it's a done deal has jumped the gun for a multitude of reasons.