From left, Denis Kudla, Sloane Stephens, Serena Williams, Jack Sock, first lady Michelle Obama, center, Melanie Oudin, Donald Young, Christina McHale, Ryan Harrison, and Madison Keys, pose for a photograph at the 18th Annual Arthur Ashe Kids? Day, the unofficial kickoff to the 2013 US Open tennis tournament, Saturday, Aug. 24, 2013, in New York. (AP Photo/Frank Franklin II)