Martina Hingis...Is she the greatest what if prodigy?

Won the Wimbledon doubles title when she was 15 years old. Youngest ever.

In 1997, Hingis became the undisputed World No. 1 women's tennis player when she was 17 years old. Youngest ever.

The only Grand Slam singles title that Hingis failed to win when she was 17 years old was the French Open where she lost in the Finals.

When she was 18, she became only the third woman to hold the No. 1 ranking in both singles and doubles simultaneously.

She didn't win another Grand Slam title after age 19.

In 2001, Switzerland, with Hingis and Roger Federer on its team, won the Hopman Cup.[ Hingis didn't drop a set in any of her singles matches during the event, defeating Tamarine Tanasugarn, Nicole Pratt, Amanda Coetzer, and Monica Seles. Federer was later quoted as saying: "I learned a lot from her, especially the two years I was here - once as a hitting partner and once as a partner with Martina. Definitely she helped me to become the player I am today."

Hingis reached her fifth consecutive Australian Open final in 2001, defeating both of the Williams sisters en route, before losing to Jennifer Capriati.

But then injuries forced her to retire at age 22. She could have been GOAT. She was the highest paid female athlete in the world for 5 consecutive years.

During this segment of her tennis career, Hingis won 40 singles titles and 36 doubles events. She held the World No. 1 singles ranking for a total of 209 weeks (fifth most following Steffi Graf, Martina Navratilova (after whom she was named), Chris Evert, and Serena Williams)