Women's tennis: 4 key takeaways from the 2018 WTA season

Most improved player of the year - Kiki Bertens

Kiki Bertens at the 2018 US Open

Dutchwoman Kiki Bertens' clay court prowess had never been in question - but in 2018, she transformed herself into an all-court threat.

In 2017, Bertens aggregated a win percentage of 72.6% on clay and a paltry 47.8% on grass and hardcourts.

Bertens won her first Premier title at the Charleston Open, defeating Julia Goerges in the final. At the Madrid Open, she defeated top-ranked players like Maria Sharapova, Caroline Wozniacki and Caroline Garcia before falling short in the final hurdle, losing to Petra Kvitova.

At the French Open, she lost a tough 3rd round match in 3 sets to Angelique Kerber. She made the quarterfinals of the Wimbledon Championships for the first time in her career, beating Venus Williams and Karolina Pliskova en route. She won the biggest title of her career at Cincinnati beating 4 Top-10 players along the way - namely Wozniacki, Elina Svitolina, Kvitova and top-seed Halep.

An injury meant Halep withdrew from the WTA Finals in Singapore and Bertens made the cut for the first time. She made the semi-finals, losing to eventual winner Elina Svitolina.

Bertens was named "WTA Most Improved Player of the Year" for 2018 and is presently ranked a career-high World Number 8.