Taylor Townsend, 23
At 19, the Chicago-born Taylor Townsend became the number one ranked junior in 2012 and and won the 2012 Australian Open junior singles and doubles titles in Australia and Wimbledon.
Most recently, she parted ways with her coach, tennis champ Zina Garrison, to return to her first coach, Donald Young, Sr. who first introduced her to tennis as a child.
Even Serena Williams tags her as one of the athletes the world should watch out for.