Patrick Mouratoglou, the coach of the World No. 1 women's tennis player Serena Williams, tells CNN's Open Court the five main reasons for her dominance of the game. Mouratoglou began coaching Williams in 2012, and their trophy tally since teaming up includes a Wimbledon title, an Olympic Gold Medal, three US Open titles, a French Open title and an Australian Open title, lifting her back up to the pinnacle of the women's game.