Roger Federer corrected Kate Middleton on Wimbledon rules after she made a stunning catch as a stand-in ball girl

• Kate Middleton and Roger Federer met the Wimbledon ball kids ahead of this year's tournament.
• At one point, The Princess of Wales made a stunning snag out of the air while patrolling the court.

Kate Middleton showcased her impressive hand-eye coordination ahead of tennis' most prestigious tournament.

But unfortunately for The Princess of Wales, snagging the ball directly out of the air is against Wimbledon's strict rules.

Kate and Roger Federer — the 20-time Grand Slam champion who won an Open Era-record eight Wimbledon singles titles during his illustrious tennis career — headed to the All England Club to meet the ball kids ahead of this year's tournament. While they were there, the megawatt duo exchanged some rallies and learned what it takes to patrol the famed grass courts during matches.

At one point, while stationed at the very back of the court, Kate caught a long shot straight out of the air. The ball girl next to her, Mollie, commended the royal for the "good catch," but Federer quickly questioned whether or not the expert snag abides by the laws of the land.

He suggested that while it might be allowed at the Australian Open, the first Grand Slam of the tennis calendar, such a move is prohibited at Wimbledon.

"Oh, yeah, are you allowed to do that?" Kate responded, redirecting the question to the expert within their ranks.

"You're not meant to catch it," the ball girl said. "You're meant to let it bounce and then get it, but good catch."

Kate and Federer tried out many of the skills crucial to becoming a Wimbledon ball kid. They completed a ball change and learned how to properly roll the balls out to the baseline. Mollie taught Kate how to stand and throw the ball to a player.

Another ball kid, Anex, told Kate that "discipline and neatness" are key to the job.

"To see the training and the dedication and the amount of time that's put into training and making sure this goes well on the day for the champions who are playing at Wimbledon, it's incredible," Kate said.

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