15. Chris Evert
Achievements as a Teen: Chris Evert burst onto the scene in 1973 at the age of 18. That year she managed to reach both the French Open and Wimbledon finals, losing both, but youth would be served. She made it back to both of those finals just a year later at 19, and let's just say history would not repeat itself. Evert now had two grand slam titles to her name before the age of 20 in what would go on to become one of the greatest tennis careers in history.
Career Recap: By the time she was finished with her playing days Evert had boasted a record of 1,309-145, the second best winning percentage in tennis history. She racked up an astounding 157 titles and climbed the ranks to reach number one in 1975. She won the Aussie Open twice, Wimbledon three times, the US Open six times, and the French Open a mind-boggling seven times. We'll do the math for you, that's 18 Grand Slam championships. Her 34 Grand Slam finals appearances are more than anyone in history. She found her place among the other kings and queens of the court when she was inducted into the Hall of Fame in 1995.