“The talk of our sport for the last two years, and, of course, deservedly because he has done things that probably no other, you know, teenager has ever done,” Djokovic said of Alcaraz during an interview last week.

Beyond all the accolades and the attention, Alcaraz is forcing the best players in the world into a devil’s choice — to change how they have trained to play for years and adapt to him, or to likely spend most of the next decade or more smothered by an athlete who plays on every inch of his side of the net and tries to hit balls to every inch of his opponent’s.

“There’s lots of power, not a lot of weaknesses, but also the all-court game, and the transition from neutral or defensive to offense is so quick,” said David Nainkin, who leads player development for the United States Tennis Association. “And now every player knows if he is going to compete with him, he’s going to have to do that as well.”

Alcaraz knows that better than anyone. He has said his goal, along with winning as often as possible, is to entertain and thrill the spectators who pack stadiums for his matches, which have also sent television ratings soaring. Winning efficiently is not enough. He wants to win spectacularly, showcasing his power and speed and touch from everywhere on the court.

“It’s dynamic,” Alcaraz has said time and again of his style.

For years, this was the sort of shift that might happen every half-decade or so, though for roughly the last 15 years, Roger Federer, Rafael Nadal, Djokovic and, for a while, Andy Murray turned the sport into an exclusive scrum of skill and wit. Each took a turn or two redrawing the tennis court to suit his style. First came Federer’s supreme and unmatched shotmaking, which ran into Nadal’s power and competitive fire, which ran into Djokovic’s relentless defense and angular creativity, which ran into Murray’s magical touch and movement.