If you enjoy superstars and drama, Day 1 at the World Tour Finals was a good place to be, thanks to Rafael Nadal and Roger Federer.
Novak Djokovic reached his first Wimbledon final. He also ascended to the No. 1 ranking for the first time. All this in a day's work.
Slick hard courts. A raucous home crowd. No Rafael Nadal. Argentina has an opportunity to collar its maiden Davis Cup title in what will be the five most important points the country has ever played.