To tell the story of 2016 is to tell the story of Angelique Kerber’s transformation from a talented grinder – one who couldn’t shake her tendency of coming up small in big situations – to the model of work ethic and persistence that grew to shine when the spotlight was at its brightest. She goes into her fourth WTA Finals as a two-time major champion, the winningest woman on tour this season, and set to clinch the year-end No.1 ranking.

The evolution began in Singapore last year, when the German capped off her 2015 season with a nervous, disappointing loss to Lucie Safarova at the BNP Paribas WTA Finals Singapore presented by SC Global. Having never qualified out of the round robin stage in her two previous attempts, Kerber found herself a set away from advancing to the semifinals. All she had to do was take a set off a recovering Lucie Safarova, who had qualified on the strength of her season but was coming off months of illness. It was supposed to be a straightforward match.

Kerber lost in straight sets. And she was furious with herself afterwards, admitting that the pressure got to her and she blinked. When she sat down with her coach Torben Beltz in the off-season, the two vowed that sort of capitulation would never happen again.

They also made it their goal to peak for the tour’s biggest events. Coming into this season Kerber had not made a major semifinal since Wimbledon in 2012. Despite a strong season that saw her win four Premier titles, she sputtered at the Slams, failing to make the second week at all four. No longer content with being a solid Top 10 player, Kerber let loose her ambition. It paid off immediately.

First came her shock run to the Australian Open title, where she went from match point down to Misaki Doi in the first round to beating an in-form Victoria Azarenka in the quarterfinals, all before playing an incredible match to beat then-No.1 Serena Williams to win her first major title.

From there she proved herself the most reliable challenger to Serena throughout the season as well as the most consistent player on tour over the course of 10 months, a rare combination in recent times. She went 59-17 on the season, making the semifinals or better at 10 events this year. She successfully defended her title at the Porsche Tennis Grand Prix in Stuttgart (her first career title defense), backed up her Australian Open run by making the Wimbledon final, and charged through the summer hardcourts, where she made three consecutive finals at the Olympic tennis event, the Western & Southern Open, and the US Open.

With the No.1 ranking on the line in New York, Kerber marched towards the final without a hitch and then capped off her Slam season with a tough three-set win over Karolina Pliskova to win the US Open and again prove that her season was not about a stellar two or four week run of tournaments, but about her ability to win throughout the season.

Through it all, Kerber proved herself to be one of the best pure competitors on tour this year. On hardcourts, clay courts, or grass, Kerber battled for every point and every match. She amped up her forehand and became a more aggressive player in 2016. When matches got tight in the past, Kerber’s counterpunching style would default into a more defensive stance. This year it defaulted into offense. She backed herself, took her chances, and took control over her own destiny.

“I played a lot of tough matches last year like three sets and especially here, as well, against Victoria Azarenka [at the US Open] last year,” Kerber said in Flushing. “That was also one match I remember where I really just pushed the balls and I was not going for it. So there were a lot of matches last year where I knew that I have to be aggressive to win it. This change also in my mind. To making the transfer is not so easy, but I think I did it well.”

After she won the US Open, I asked Kerber what was the loudest, most frequent criticism of her game when she was a teenager. The woman who has tallied a 17-5 record in three-set matches this year, winning two pressure-soaked three-set Slam finals, didn’t hesitate with a response.

“Actually when I was starting when I was 16 or 17, my fitness was the worst,” Kerber said. “Everybody was telling me that I needed to train more my fitness. Ten years later my fitness is the best and I can move forever on the court.

“I was too slow, I couldn’t play three sets because I was not prepared for this. Also conditions, when it was really hot I was like ok, I have to run again. That’s changed. Everything’s changed. I think you have to learn how to work very hard. I think that was a process for me, to really see that when you’re working really hard on your fitness your results are better.”

“When you know you can run forever on court and you’re not worried that you can play three sets. I think this is really important for your confidence that you can play like two, three hours and you can go for it. I think I was working a lot on these things. This gives me a lot of confidence, especially also in Australia where it’s really hot.”

Kerber’s physical and mental transformation shows in the titles she’s won this year. Through the searing heat of the Australian Open, the nerves of defending the biggest German title in Stuttgart, and rising through the New York pressure cooker, Kerber never wavered in her belief in her game and her abilities. Hers is a story that should inspire the other women in the locker room, those who may not have been given the power shots that tend to define the modern game. Speak to Kerber enough and you’ll realize one of her key phrases when discussing the key to her game or her season is “going for it.”

In 2016, no one seized her moment like Angelique Kerber.

All photos courtesy of Getty Images.