Six months ago, having just won the Australian Open one year after being deported from the country, Novak Djokovic collapsed in the arms of his family and his coaches in a moment of strained ecstasy.
He had drawn even with Rafael Nadal in the race for most Grand Slam singles titles. When he finally took the lead last month, at the French Open, he fell onto his back in the red clay of Roland Garros and then called winning that tournament, his 23rd Grand Slam title, his version of scaling Mount Everest. He donned a warm-up jacket emblazoned with the No.