Hamilton back in action with Ferrari: Is that an advantage over rivals?

Hamilton's start at Ferrari got off to a busy start. The seven-time world champion is set for his third test day (and he did a run at Fiorano after his presentation), meanwhile, for example, Max Verstappen is yet to sit in a Red Bull car this year - or at least it was a secret one. Does having so many days under his belt give the Briton the advantage over his rivals?