NEW YORK -- Playing conditions have been a talking point over the first few days of this year's US Open, with many players weighing in on the court speed and the state of the balls.
The problem is, players can't seem to agree.
"The court speed, I can't recall actually what was the year when it changed, when it started being slightly quicker than what it used to be," Novak Djokovic said at Flushing Meadows on Wednesday. "But it's been pretty much the same speed for some years."
The US Open is the only major to use different balls for the men's and women's events -- both use Wilson, but the men's "extra duty" ball is slightly heavier. Court speed and how fast or slow the balls are playing can be affected by temperature, wind and humidity, but whatever the weather, players always seem to disagree among themselves. John Isner once told reporters that he didn't really see the difference between clay courts and grass courts.
US Open organizers insist the balls are the same as last year and the courts are the same, medium-fast speed. Alexander Bublik called them "pretty fast" and Alex De Minaur said they are "quick and skiddy," but Australia's Jordan Thompson had other thoughts after his first-round win.
"Usually it's a lot faster," he said. "But I wouldn't call these courts fast this year.
"I feel the balls are really soft, especially when it got cold. Obviously, when it gets cold, it's going to get slower, but even in the day, I mean, I feel like usually the balls get lighter and older now they feel really soft and heavy. It's just so frustrating. You're coming here expecting to be the same as every other year, and it's just not."
Jessica Pegula, the No. 4 seed, said some players are better than others at judging court speed.
"I think some people are really in tune to it maybe too much [and] some people just don't even care," she said. "They're, like, I don't know, it feels kind of this.
"I don't know what's right or wrong, it's probably good in a sense to not overthink it, but I do think sometimes maybe a lack of awareness might make you change your decision or maybe not being aware can also hurt. But I think it just depends. Everyone's personality is so different when it comes to court speed and balls and stuff like that."
Daria Kasatkina said she thought the balls were flying.
"The surface is pretty fast," she said after her first-round win. "The balls are not fluffing up at all. They're opposite. They're becoming rocks. It's interesting because the more you play, the harder they are, and less controllable they are. They're becoming completely bald and when you try to squeeze them, it feels there is a lot of pressure from inside, which is a bit weird.
"In normal conditions, when the ball is older, it becomes softer and it is more difficult to make a winner. Here it's like just flying, boom, boom, boom."
Craig O'Shannessy, the respected data analyst and coach, said players are often the worst judges.
"It's because it's all about their personal preference," he told ESPN. "When they say it's fast, that needs to be prefaced with 'it's fast for them,' or 'it's slow for them.' Certain game styles, players from Spain, Argentina, South America, they're going to enjoy a slower surface, with the ball that bounces up more, and if the court is not behaving that way, if it's maybe even coming through lower at the same speed, it's going to feel different for them, and they could quite easily say it's fast when maybe it's just lower."
De Minaur said the balls had played differently in every event of the North American summer.
"A lot of players, we were scratching our heads, because we don't understand, we played with this ball at the US Open, and we've never felt like, jeez, it's uncontrollable, or we can't feel the ball in the strings [as we did] in the lead-up tournaments. You could have asked any player in the draw and they would have had the same feelings.
"So for me, it feels great to be here. It feels like comfortable conditions. It's obviously quick and skiddy, but I've always enjoyed it."
Djokovic said he had been discussing the state of the balls with his fellow players.
"I've been hearing that a lot of the players think that finally there is some consistency with the balls that they have used in the US Open Series tournaments coming into the US Open. Most of the players I have spoken to, they say that now, they're almost the same.
"That's good to hear, and we can instantly see less injuries with the joints obviously that we have seen. There was an unfortunate trend of injuries, I think was it last year or two years ago? So I think that has to be obviously taken seriously, and to make sure that there's no big fluctuation in terms of the quality of the balls."
O'Shannessy said court speeds will vary according to how much tennis has been played on them.
"I'm working with Gabriel Diallo here, and we've practiced on a number of courts, including Ashe, and his take is, every court is different," O'Shannessy said. "Some are faster than others. A lot of it comes down to how much wear they're getting, how much play they're actually getting.
"You've also got to preface when you ask the player, is the court faster, at what time? What was the temperature, and how was the wind? And then you're starting to get a better answer. But when you ask a player, it's very much related to them."
Pegula said all the courts at Flushing Meadows play differently.
"The back courts are a lot faster than Ashe," she said. "Ashe is kind of slow, almost, a little bit. Armstrong always is a little bit faster than Ashe. I definitely have played on a lot of these courts here and they're definitely not the same. They try to make it as much the same as they can but they have to lay them all down at different times, different days, and the temperature and all this stuff really changes that process."