Iga Swiatek has been able to develop her game since hiring Wim Fissette as her coach last year.
Swiatek announced her split from long-term coach Tomasz Wiktorowski, who is now working with Naomi Osaka, in October last year.
Since then, Swiatek has been working with Wim Fissette, but it has not been completely plain sailing.
However, this partnership appears to be gelling now, with Fissette helping Swiatek win Wimbledon for the first time after improving one element of her game in particular.
Photo by David Kirouac/Icon Sportswire via Getty ImagesIga Swiatek explains how Wim Fissette has helped improve her serve
Serving has been seen as a potential weakness for Swiatek over the years, despite her Grand Slam success since the age of 19.
This is something that Fissette set out to improve at the start of his tenure coaching Swiatek, and it appears to have worked.
Swiatek now has a flatter serve, which has enabled her to consistently improve the speed of it, something she has admitted she never thought was possible.
After beating Sorana Cirstea to reach the Cincinnati Open quarterfinals, Swiatek revealed in her post-match press conference that she now has belief in her serve.
“Honestly I am always the kind of player who needs to see the proof, if the serves are going to go in I will be convinced,” said Swiatek.
“I would say maybe at the beginning of the season and when I started working with Wim I did not believe I could serve 185kmph and 180kmph consistently so I think he helped me with reaching these higher speeds.
“We were working a lot of hours on precision, so I think I used it pretty well at the Australian Open and at Wimbledon. Now I need to find it again with the balls here. But I think I am more brave with my decisions and I wouldn’t say there are any hurdles, I just needed to believe it.”
Iga Swiatek’s serving statistics at the Cincinnati Open this year
Despite Swiatek increasing the speed of her serve since hiring Fissette, it has not been noticeably more effective at the Cincinnati Open this year.
The world number three has admitted that she is still trying to adapt to the balls during the North American hard court swing.
At the Cincinnati Open this year, Swiatek has hit more double faults than she has aces and has only just hit more than half of her first serves in the court.
This is in comparison to Wimbledon, where Swiatek’s first serve percentage was up at 64.1%.
Iga Swiatek’s serveAt the Cincinnati Open in 2024At Wimbledon 2025At the Cincinnati Open in 2025Average Aces per match3.53.42.5Average Double Faults per match2.252.43Average First Serve %63.75%64.1%55%Average First Serve Win %71.75%79%76%Average Second Serve Win %51.25%53.4%50.5%Average Games Broken per match2.250.91.5
Swiatek will now look to reach the semifinals of the Cincinnati Open for a second consecutive year, when she plays in-form player Anna Kalinskaya.
Despite being the favourite ahead of the upcoming quarterfinal match, Kalinskaya beat Swiatek in their only previous meeting at the Dubai Tennis Championships in 2024.