NEW YORK, NY - SEPTEMBER 02: (L-R) Former tennis player Martina Navratilova teaches Barbora Zahlavova Strycova of the Czech Republic to use a wooden tennis racket during a video shoot on Day Nine of the 2014 US Open at the USTA Billie Jean King National Tennis Center on September 2, 2014 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Matthew Stockman/Getty Images)
