Coaching changes have been frequent on the WTA tour, to say the least. (AP)

Naomi Osaka, Simona Halep and Sloane Stephens, who have combined to win four of the last six women’s Grand Slam singles titles, have all made coaching changes this year. It was a strange time of the season for all this to happen, but particularly in these cases.

Performance certainly wasn’t an issue for Osaka, winner of the last two majors. When something’s working, why would you change it? I didn’t quite understand the move—but relationships drive coaching partnerships, and if there’s unhappiness, I get that.

There are other reasons for coaching splits, including under-performance and pay. Family needs are also a factor, as we saw with Halep’s former coach, Darren Cahill, who wanted to spend more time with his children; or with Toni Nadal, who shifted his focus to the Rafa Nadal Academy.

There can also be a difference of opinion in the direction of the player’s development, or the work ethic of the player, that can cause a fracture. All coaching relationships are delicate, and can be difficult to maintain when the younger person is paying the check.

Here’s a closer look at three that didn’t hold up:

Naomi Osaka: It was so strange reading the transcript of her interview after she won the Australian Open, when Osaka was asked what she and Sascha Bajin discussed before the final. “I didn’t talk to him,” Osaka replied. There was something going on there. There was a lot of discussion amongst pundits about whether it was a financial issue, but Osaka batted that away after she was asked about it in Dubai.

It just seems like the relationship fell apart at some point. I think back to the US Open, in the warm-up area, where Bajin was dancing and they were having so much fun. It’s sad to see that they lost that connection.

 
 
 
 
 
 
 
 
 
 
 
 
 

‪Just for laughs ????‬

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Simona Halep: This was a family decision for Cahill, who wanted to spend more time at home than on the road. There wasn’t a problem in his relationship with Halep, from what he said. I believe him; he’s an honest shooter.

Halep tried a brief coaching stint with Thierry Van Cleemput. It lasted just one week, but sometimes that’s all you need to get a feel for whether the communication will work or not, and whether personalities will mesh.

Sloane Stephens: Stephens has the ability to flip a switch, and all of a sudden she’s on fire. We saw that in 2017, when she won the US Open out of nowhere, and that same switch turned off shortly after. Then she won Miami and finished runner-up at Roland Garros. She’ll say, “It’s nothing to panic about, guys.” And then she finds it. She knows that it’s in there, with or without Kamau Murray in her corner.

Osaka has since started working with Venus Williams' former hitting partner Jermaine Jenkins, while Bajiin has joined Kristina Mladenovic's team. Halep rehired a former coach, Daniel Dobre, ahead of Miami, while Stephens is still officially coach-less, but being advised by U.S. Fed Cup captain Kathy Rinaldi.