Gauff could hit some of the hardest first serves on tour, but her iffy second serve and wonky forehand had never been a secret. When she hits a forehand, she uses what’s known as an extreme Western grip,

MELBOURNE, Australia — There’s a young woman who looks a lot like Coco Gauff at Melbourne Park for the Australian Open. She has the same fiery, competitive eyes, the same tendency to break out in a giggle in the middle of a sentence and the same number of titles.

It was a meaningless hit-and-giggle session, so Coco Gauff was calling out how fast she would try to hit some serves.