NEW YORK - AUGUST 27: Spidercam aerial camera system used for broadcast from Arthur Ashe Stadium at the Billie Jean King National Tennis Center during US Open 2013 on August 27, 2013 in New York - Stock Photo & Image

NEW YORK - SEPTEMBER 3 Professional photographer and spectators during US Open 2013 at Billie Jean King National Tennis Center on September 3, 2013 in New York

NEW YORK - SEPTEMBER 3, 2018: Professional sport photographers at the 2018 US Open at Billie Jean King National Tennis Center in New York

NEW YORK - SEPTEMBER 1, 2018: US Open logo at Arthur Ashe Stadium at Billie Jean King National Tennis Center in New York. US Open is a final tennis major comprising the Grand Slam each year

CINCINNATI, OH - CIRCA 2011: tennis match Novak Djokovic vs Andy Murray at Lindner Family Tennis Center on Western & Southern Open tournament finals in Cincinnati, OH, USA at summer 2011.

NEW YORK - AUGUST 25, 2014: Line judge during match at US Open 2014 at Billie Jean King National Tennis Center

NEW YORK - SEPTEMBER 6, 2016: US Open cleaning crew drying tennis court after rain delay at Louis Armstrong Stadium at Billie Jean King National Tennis Center in New York

NEW YORK - AUGUST 26 Line judge during first round match between Venus Williams and Kirsten Flipkens at US Open 2013 at Billie Jean King National Tennis Center on August 26, 2013 in New York

NEW YORK- AUGUST 25, 2015: Arthur Ashe Stadium at the Billie Jean King National Tennis Center ready for US Open tournament in New York

NEW YORK - SEPTEMBER 3, 2018: Professional sport photographers at the 2018 US Open at Billie Jean King National Tennis Center in New York

NEW YORK - SEPTEMBER 1 Arthur Ashe Stadium during US Open 2013 third round doubles match at Billie Jean King National Tennis Center on September 1, 2013 in New York

MELBOURNE, AUSTRALIA - JANUARY 25, 2019: TV camera with Tennis Australia logo during 2019 Australian Open match at Australian tennis center in Melbourne Park

NEW YORK - SEPTEMBER 3, 2019: Arthur Ashe Stadium at Billie Jean King National Tennis Center during 2019 US Open match in New York

NEW YORK- AUGUST 25, 2015: Arthur Ashe Stadium at the Billie Jean King National Tennis Center ready for US Open tournament in New York

NEW YORK - SEPTEMBER 3, 2018: Arthur Ashe Stadium at the Billie Jean King National Tennis Center during night session at the 2018 US Open tournament in New York

NEW YORK - SEPTEMBER 9: US Open 2013 champion Rafael Nadal during final match against Novak Djokovic at Billie Jean King National Tennis Center on September 9, 2013 in New York

NEW YORK - SEPTEMBER 6, 2016: Ball boys on Arthur Ashe Stadium during US Open 2016 at the Billie Jean King National Tennis Center in New York

NEW YORK - SEPTEMBER 1, 2019: 20-time Grand Slam champion Roger Federer of Switzerland in action during the 2019 US Open round of 16 match at National Tennis Center in New York