Tennis' biggest stars are unhappy with the French Open's new balls that 'you wouldn't give to a dog to chew'

• Tennis' biggest stars are unhappy with the new tennis balls at this year's French Open.
• Reigning champion Rafael Nadal as well as Novak Djokovic, Dominic Thiem, and more have said the balls have felt heavier after the tournament switched from Babolat to Wilson-brand tennis balls.
• British star Dan Evans went as far as to say that "some of those balls we were using you wouldn't give to a dog to chew" after losing a five-set match.

Tennis' biggest stars are facing a unique problem at this year's French Open.

High-profile players like twelve-time Roland-Garros champion Rafael Nadal, world No. 1 Novak Djokovic, 2020 US Open champion Dominic Thiem, and more have complained that the tennis balls at this year's tournament have felt heavier than in years past.

After losing a five-set match to Japan's Kei Nishikori in the opening round, British star Daniel Evans even went as far as saying that "some of those balls we were using you wouldn't give to a dog to chew."

"It's brutal," Evans said per Tennis.com. "I think the balls are the biggest thing."

"Maybe they got it a little wrong with the balls," he added. "It's tough to get that ball to go anywhere... That ball's a bit too heavy, I think."

The French Open switched from Babolat to Wilson-brand tennis balls this year. And though Wilson claims the balls are "crafted for ideal performance on clay" on its website, Evans is far from the only player dissatisfied with the switch. Nishikori acknowledged that "there's less bounce" from the balls, while Nadal called them "super slow" and "heavy."

Djokovic, for his part, agreed with his opponents that "the balls are heavy" but acknowledged that there may be other factors at play besides this year's brand switch.

"But also it's probably because we are also almost in October, and it's very cold," Djokovic said, per Essentially Sports. "The clay is also heavy and wet. Just overall conditions are also affecting the ball itself. It's very hard to say whether the ball is heavy in general or is it because we are playing under these kinds of slow and heavy conditions?"

Tennis balls travel slower through cold air than warm. Likewise, rainy, wet conditions can result in balls that are water logged and more likely to pick up clay, making for slower and heavier balls than those used on dry days and on different surfaces.

According to Duke University professor of mechanical engineering Adrian Bejan, an expert in thermodynamics who spoke with The New York Times on the matter, how much slower the balls move "will depend on the assumed temperature difference between warm and cold weather."

Though a large contingent of contenders at Roland-Garros have not been fond of the switch, one top player — US Open runner-up Alexander Zverev — actually prefers the new balls.

"The balls now are way better than before," the 23 year old said after his first match at the tournament, per journalist Nikolaus Fink. "The Babolat balls were the worst of all time."

Regardless, players have to adjust to the conditions thrown their way. But for the most part, they're grateful to be competing the Grand Slam after a year of uncertainty and tumult in tennis — and the world at large.

"It's nice that we have the chance to play," WTA No. 2 and Italian Open winner Simona Halep said.

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