In 3 days, on a tough course, he's only had a handful(or less), of miscues. Not all of the same nature, which is good. imo, this is the best swing he's ever had as it looks so easy & free. Not going all out on every swing, yet still killing the ball & placing it where it needs to be. If the swing and attitude are the same tomorrow as it has been the past 3 days, it is a done deal.
BUT......if Rory had had even a trifling of luck today, TW would not be in the lead. And we probably would not be having this discussion.