LAS VEGAS, NV - OCTOBER 12: Tennis player Stefanie Graf participates at the Mylan World TeamTennis Smash Hits charity tennis event at Caesars Palace on October 12, 2015 in Las Vegas, Nevada. (Photo by David Becker/Getty Images)
LAS VEGAS, NV - OCTOBER 12: Tennis player Stefanie Graf participates at the Mylan World TeamTennis Smash Hits charity tennis event at Caesars Palace on October 12, 2015 in Las Vegas, Nevada. (Photo by David Becker/Getty Images)