Naomi Osaka had more coaches than she won titles last year but will be hoping that her latest trainer can propel her to a successful defence of her Australian Open crown.
The 22-year-old Japanese had a rollercoaster 2019, winning in Melbourne and topping the world rankings but then ploughing through three coaches before settling on Wim Fissette in December.
The 39-year-old Belgian has worked with a raft of former world number ones including Kim Clijsters, Victoria Azarenka and Simona Halep.
At the Brisbane International last week, the world number three described what drew her to Fissette.
"(I wanted) someone that's calm and knowledgeable and can work with the team dynamic," said Osaka, beaten in the Brisbane semi-finals by second-ranked Karolina Pliskova.
"Because my trainer, my physio... I've had them for more than two years and they're like my family at this point," said Osaka.
"So I felt like anyone that I brought in now should be able to work well with them.
"I know that he's worked with a lot of top players and I feel like I'm learning from everything that he says, and I try to apply it."
Osaka's up-and-down 2019 started with a bang, beating Petra Kvitova in three epic sets in Melbourne for back-to-back Grand Slam titles, having triumphed at the 2018 US Open.
But two weeks later she abruptly ended her successful partnership with coach Sascha Bajin. Osaka cryptically said that she was not prepared to place "success over happiness".
Osaka, whose mother is Japanese and father Haitian, then teamed up with Jermaine Jenkins but their association lasted barely six months and coincided with a marked downturn in form.
After the disappointment of exiting in the fourth round at Flushing Meadows -- where she was defending champion -- Osaka called it quits with the American.
- 'I've been frantic' -
She travelled to the Pan Pacific Open in September in her birth city of Osaka with the man who knows her best in her corner -- her father Leonard Francois.
Osaka always made it clear that it was only a temporary measure -- she joked that his nerves could not take it -- but having her father as coach brought immediate success.
She triumphed in Japan and took that uptick to Beijing, where she ended the long unbeaten run of teenager Bianca Andreescu, in the first instalment of a potentially long rivalry at the top of women's tennis.
With her father courtside, Osaka defeated world number one Ashleigh Barty in the final of the China Open to make it back-to-back titles.
However, her season ended prematurely when she pulled out of the year-ending WTA Finals in Shenzhen with a shoulder problem.
Injury and the game of coaching musical chairs seemingly behind her, Osaka appears primed to make a strong defence in Melbourne, where Serena Williams is chasing a record-equalling 24th major title.
Osaka squandered match point in losing to Pliskova on Saturday in Brisbane and said afterwards that she needs to control her emotions better on court.
"I feel like ever since I won Osaka -- even in Beijing -- I've been kind of frantic and losing my cool a little bit and I've been throwing my racquet," she said.
"So that's something that I think I need to do better on heading into the Australian Open."
Naomi Osaka is defending a Grand Slam title for the second time
Wim Fissette is Osaka's fourth coach in a year
Osaka beat Petra Kvitova to win last year's final in Melbourne
Naomi Osaka (left) and Serena Williams share a lighter moment in Melbourne Wednesday during the Rally for Relief event in support of the victims of the Australian bushfires