Forty-three years after its creation, the Women’s Tennis Association still bills itself as “the global leader in women’s professional sport.”

This is no puffed-up claim. With close to $130 million in prize money available in 2016, tennis continues to provide paydays like no other women’s sport. See the $3.3 million that Flavia Pennetta earned for winning the 2015 U.S. Open. The sport has also produced a steady stream of truly global stars with staying power, from Chris Evert and Martina Navratilova in the WTA’s early years to Maria Sharapova, who may not play much longer, and Serena Williams

But it is just as clear that the WTA is on borrowed time when it comes to global leadership. Women’s soccer, a still-drowsy giant, continues to stir. Soccer is a team game with fewer barriers to entry than expensive, technically daunting tennis, and with an estimated 30 million players worldwide, it already has a bigger amateur base. The money should eventually follow, even if professional leagues are still struggling for footing.

The women’s game’s international reach and societal resonance are potentially huge, and it seems symbolic that when the latest FIFA women’s soccer and leadership conference opens Monday in Zurich, the keynote speaker will be none other than tennis trailblazer Billie Jean King.

“It’s not like they don’t know it, but I think this is their moment of truth because of the corruption and all the things they’ve had to deal with lately,” King said of FIFA, soccer’s governing body, in a telephone interview last week. “And I am a big believer when there’s a crisis, there’s opportunity. It’s a moment to have historic transformation at FIFA, and I will make my case.”

King intends to argue that expanding the women’s game and increasing women’s influence on the game should be a big part of that transformation. And with Gianni Infantino, FIFA’s newly elected president, expected to be in attendance, King will apparently be preaching to the converted.

“The future of soccer belongs to women,” Infantino said last month as he opened FIFA’s new museum.

King, 72, has made so many cases through the years when it comes to women’s rights: from the founding of the WTA to her battle-of-the-sexes victory over Bobby Riggs to the creation of the Women’s Sports Foundation to the continuing fight for implementation of Title IX, the U.S. law that provides — in theory at least — equal access to collegiate sports for women.

Though King declares herself an unreformed optimist, there are undercurrents of bitterness. It has been a lifelong tussle, and while progress is evident, the pace of change in the women’s sports movement and the women’s movement at large has been a frustration.

“People don’t care about us as much, and I’m talking about enthusiasm on the outside,” she said. “I’ll give you a perfect example. Obama, being the first black president, everybody was beside themselves.”

“With Hillary,” King continued, referring to Hillary Clinton, “they could care less that she’s going to be the first woman. OK, I don’t care about their personalities. I realize Obama is much easier-going. Hillary even said it. She said: ‘Look, I’m not Bill Clinton or Barack Obama. I definitely don’t have their wonderful, warm personalities, no question.’ She said it very truthfully, which is very refreshing when people are always truthful and specific. And you know no one is excited about that.”

This is, of course, debatable. A Hillary Clinton victory in November would certainly be viewed as a breakthrough in many quarters, but King, who expresses eagerness for it, also sounds impatient.

“I’ll probably use this line; I use it a lot,” she said of her Monday speech. “When you read about history you think it’s gone very fast, but when you live it, it’s very slow. I’m 72 now and look at how slow everything is.”

She pointed to the continuing disparity in women’s and men’s earnings for equal work; the ongoing economic struggles of women of color and the big gap that remains in female and male representation in the U.S. Congress.

“I think it will take another 150 to 200 years probably,” she said. “But you have to keep fighting for it. Each generation has to do their part.”

Still, some generations have an opportunity to do more, and in sporting terms, which are hardly the most important terms, this generation of women’s soccer leaders clearly has a window — all the bigger with FIFA’s new leadership eager to forklift the organization out of the mud.

Gender equality sounds a whole lot better than widespread bribery.

In one of his first official acts as FIFA president, Infantino will open the conference Monday, and he is expected to follow the panel discussions, which are set to include Abby Wambach, the recently retired American star; Sunil Gulati, the president of U.S. Soccer; and Moya Dodd of Australia, a soccer official who has been the driving force in the recent push for women within FIFA.

It can be considerably more fun and affirming to ride the growth curve than to try to shore up the status quo. Giving women’s soccer a boost was a big part of Infantino’s campaign platform, and there has been structural change under duress as well. Reforms passed shortly before his election now guarantee six women on the enlarged, 36-member FIFA council.

“His manifesto is beautiful; I’ve been reading it,” King said of Infantino. “I think the one-up we may have, and this usually helps a lot, is that he has four daughters. And I’m hoping that I can reach his heart and reach the heart of others who have daughters because that’s when we get help.”

King is no soccer expert. She said, surprisingly, that she did not watch much sports these days, but she has been an occasional mentor to some of the pioneering American professional players, including Julie Foudy, the sharp Stanford-educated former midfielder. King said she had counseled Foudy in the push for more income and influence for the U.S. women’s national soccer team.

This time, King sought advice from Foudy on what she should say to FIFA. Though her speech was still a work in progress last week, her thesis was already clear.

“It’s about our culture; it’s about women and what does it say to the world?” King said, her familiar voice rising. “Don’t you want to leave in the next 50 years a legacy that is just so different from this past legacy? I mean seriously!”