How do you follow the Greatest Generation? It’s a question tennis has tried to answer for at least a decade. Serena, Roger, Novak, Rafa: all of them are over 30, and they’ve combined to win 75 Grand Slam singles titles—but none of them are going away quietly. When they do, who will fill their very large shoes?

As you’ll see in The 21 & Under Club, the future of tennis is still coming, and coming soon. While it may not produce a 20-Slam winner, it’s clear that the game will be in good hands. Interesting hands, too: one thing we know for sure is that this new generation of players will infuse the tours with a wide and refreshing range of styles, personalities and backgrounds. When the Greatest Generation says goodbye, we can feel good about welcoming this cast of players to the courts.

Instagram: bigfoe1998

Most-Liked Photo of 2019: Celebrating in Melbourne, with sleeve pulled up

Rare is the player who loses a match in straight sets and comes away looking like a winner. But Tiafoe, who turned 21 during his breakthrough Australian Open run this year, made so much progress over five rounds that his potential—immense as it already was—needed to be recalibrated.

If Tiafoe can reach the last eight of a major at this age, odds are, he can go at least one round farther at some point in his still-nascent career.

“He’s trying to define his game—and that’s a good thing,” says Paul Annacone.

A fan favorite, Tiafoe imparts his physical gifts into every shot he hits. He can play with touch when needed, and the best-of-five set format at Slams may suit him best of all. Remember, he almost beat Federer in the first round of the 2017 US Open.

“He’s so gifted that he can do a lot of different things,” says Annacone. “He’s got power, he can hit winners, and he’s great athletically. “He’s going to keep getting better and better.”

bigfoeonthecomeup, reads Tiafoe’s Instagram profile. It’s a warning his opponents would be wise to heed.

Read more of The 21 & Under Club