Djokovic comfortable in Grand Slam driver's seat

Cold-blooded consistency is making Serbian superstar one of the best ever

Novak Djokovic could not find his keys.

Alone in a parking lot outside Arthur Ashe Stadium at about 2 am on Monday, a handful of hours after beating Roger Federer in the US Open final for his third major title of 2015 and 10th overall, there stood Djokovic.