PARIS: No one went quite so far as to blame a Day 1 loss at the French Open on—or credit a victory to—the different tennis balls being used this year at the clay-court Grand Slam tournament.

There were, though, plenty of opinions about the switch of spheres.

They’re harder, most agreed. They’re fluffier, a few thought. They’re better, some suggested, for players such as Rafael Nadal, who use a lot of spin. They’re faster, at least at first, then tend to slow after a few games, was the consensus. They’ll help powerful servers.

Any of those elements could affect matches, players said, and possibly their health.

“In the locker room, a lot of the girls … (are) coming in with a lot of shoulder issues. They say the balls are pretty hard,” Bethanie Mattek-Sands said Sunday after coming back to beat Arantxa Parra Santonja of Spain 2-6, 7-6 (5), 6-3.

“I think it kind of translates to they’re going fast through the air,” the American said. “I don’t mind that. I actually like it if it’s fast-paced.”

Under a five-year contract that begins in 2011, the French Open is moving to Babolat balls from Dunlop. It’s not every day that a Grand Slam tournament changes its ball brand. Or even every century. Wimbledon, for example, has used Slazenger since 1902. The U.S. Open has used Wilson since the late 1970s; the Australian Open switched to Wilson in 2006.

Pro tennis players can be rather persnickety about the equipment they use, noticing any slight tweak as they move from tournament to tournament. The European clay circuit events leading up to the French Open use Dunlop balls.

“The balls are pretty strange,” 14th-seeded Stanislas Wawrinka of Switzerland said after winning Sunday. “Obviously I do notice a big difference from last year.”

The 2010 women’s runner-up, Sam Stosur of Australia, wasn’t so sure.

“They might be a little bit harder,” said Stosur, who defeated Iveta Benesova of the Czech Republic 6-2, 6-3 in this year’s first match on Court Philippe Chatrier. “I don’t think that’s a bad thing or a good thing. It’s just what they are.”

Benesova did think the balls played to Stosur’s big hitting.

“It helps someone like her,” Benesova said. “They are much faster. I feel like I cannot control them as well as the previous ones. So I like the ones before better. I don’t know why they changed it. … These are for the big hitters’ advantage, for sure.”

Another fan of the new ball is Ruben Ramirez Hidalgo, a 33-year-old Spaniard who had lost in the first round in 13 of his 14 previous appearances at Grand Slam tournaments but beat No. 19 Maric Cilic on Sunday.

“I like those new balls. They suit my game,” he said. “When you put some topspin, they bounce back higher—and it’s good for me.”

Monday’s schedule features Novak Djokovic, who is 37-0 this season; 16-time Grand Slam champion Roger Federer; defending champion Francesca Schiavone and No. 1-ranked Caroline Wozniacki. They’ve already had a chance to practice in Paris with the new French Open balls.

And they’ve had a chance, like others, to render judgment.

“The balls are very, very fast, so it’s really difficult to control,” Djokovic said. “Maybe it’s going to favor the servers and the big hitters. But you never know. I mean, it still is clay.”

Noted Federer: “The balls are faster, indeed. It might be a bit difficult in the beginning, but in the end, they’re not that fast.”

Schiavone—like Nadal—happens to use a racket made by Babolat and so she spoke to some at the company about the balls.

“They’ve very similar—or maybe the same,” Schiavone said. “The weather makes a big difference with the balls and how big they get. I think they’re the same as last year, with a different logo.”

That, as it happens, is the official stance of the tournament itself.

French Tennis Federation spokesman Christophe Proust said the Babolat balls are made “the exact same way” as their Dunlop predecessors. If players get the sense that this year’s balls travel faster and bounce higher, Proust said, it’s because the weather has been dry and warm lately.

“It hasn’t been raining for two months now,” Proust said. “The playing conditions are much more faster than last year. The players don’t remember that last year, when they arrived in Paris, the weather was very damp. The balls were waterlogged; they didn’t bounce back at the same height.”

There are more than 300 types of balls approved each year by the International Tennis Federation, and tournaments must pick from that list.

“Every brand that is submitted for approval is subjected to number of tests — mass, weight, size, the diameter of the ball, a test for compression to see how stiff it is or how resistant it is, and finally how high it bounces,” said Stuart Miller, head of the ITF’s science and technical department. “Every ball of tennis used at any event—including Grand Slams—is subject to all of those tests. The tournament is free to select any ball it likes.”

Three-time major finalist Andy Murray wishes balls could remain consistent, at least as the tour swings through a stretch of events on a particular surface.

“For the players’, wrists, joints, your elbow and shoulder, it makes sense to just stick with the same ball,” Murray said. “It’s not the problem with the (Roland Garros) ball. The ball probably helps me; the ball is quite fast. But I would just rather we played with the same ball throughout each part of the season. During the grass, I’d rather all the tournaments were with Slazenger. That’s what I would prefer. Well, I think that’s what most of the tour would prefer, to be honest.”