Just listing all the records and accomplishments that Billie Jean King has garnered in her lengthy career could be a book of its own.

In ALL IN, her autobiography written with Johnette Howard and Maryanne Vollers, we see an overarching theme to King’s life and career: work hard and play fair, not only at tennis but in life. It’s an intimate look at the people and moments that shaped King both on and off the court. The young bespectacled girl from Long Beach, California, who was once told by a coach, “You’ll be good because you’re ugly,” went on to revamp amateur and professional sports for women, winning 20 Wimbledon championships --- 39 Grand Slam titles overall --- and scoring 90 million viewers who tuned in to watch her beat Bobby Riggs in the famous “Battle of the Sexes” match. In the parlance of today, she is a badass.

Both King and her younger brother, Randy, were into sports at an early age. But from the moment she first stepped onto a tennis court, she knew this was what she wanted to do with her life, even going so far as to tell her mother, “I’m going to be No. 1 in the world.” She saved up her money from odd jobs to buy her first racket. But even with her incredible determination and talent, King would soon come up against the inequality of the sport. She was barred from posing in a photo of junior tennis players at the Los Angeles Tennis Club in 1955 because she opted to wear the white shorts her mother made her rather than the traditional tennis dress.

"Just listing all the records and accomplishments that Billie Jean King has garnered in her lengthy career could be a book of its own.... ALL IN [is] a thorough and detailed testimony of her passion, perseverance and heart..."

Undeterred, King focused on improving her game and quickly rose in the ranks of local and regional titles, turning pro in 1959, continuing to play while she attended college. In 1961, she and her partner, Karen Hantze Susman, became the youngest pair to win the women’s doubles title at Wimbledon. In 1965, she married her longtime boyfriend, Larry King, who was attending law school. They made a great team, establishing a life together while she continued to advance her game.

But it didn’t take long for King to come up against the politics of the sport: “I got a big taste of tennis’s insider politics almost immediately. When the USLTA board convened…I was forced to share the 1965 top spot with Nancy Richey, who had been bumped down to No. 2. It was the first time the ranking committee had been overruled in eighty-one years.” (This effort was led by the organizer of a midwestern tournament that King had to skip that year, so the ruling was payback.)

However, King did not let these glitches hold her back. In the mid-to-late ’60s, she started picking up titles left and right. The young girl from Long Beach made good on the promise to her mother to become No. 1 in the world, which she did in 1966, and held the top spot for five additional years.

King saw the inequality in tennis and other sports, not to mention the archaic rules, and it didn’t make sense to her: “When I looked around tennis, I thought the USLTA’s treatment of women and its stance on amateurism were both outdated. Lawn tennis started in the English countryside as a social pastime for wealthy Victorians, and women had always been part of the tradition. And yet we were treated as second-class citizens, even if we played on the same size courts and in many of the same tournaments as men. To a lot of us, merely allowing women in the door wasn’t good enough.”

Always lobbying for equal pay for female athletes, King --- along with eight other female tennis players --- joined the Virginia Slims Circuit in 1970. The following year, she became the first female athlete to make over $100,000 in prize money. At the height of her career in 1973, she used her ranking to leverage the formation of the Women’s Tennis Association and became its first president.

To further prove her point that people were just as interested in seeing female athletes as their male competitors, King accepted Bobby Riggs’ challenge to play the “Battle of the Sexes” match in 1973 at the Houston Astrodome. The 55-year-old Riggs claimed that the female game was inferior, and she agreed to the circus-like event to prove a point. King beat Riggs in straight sets: 6-4, 6-3, 6-3. After the match, she said, “I could finally exhale…. I had to win to protect and advance the hard-won progress women were making everywhere by then, not just in tennis.”

King was used to garnering headlines on the court, but in the 1980s, it was her private life that was put under a microscope when her relationship with her secretary, Marilyn Barnett, was revealed. For years, she dodged answering questions about her sexuality, but after her divorce from Larry in 1987 (the two continue to have a close friendship), she met and fell in love with her doubles partner, Ilana Kloss, and they have been together ever since. Always an advocate for equality and social justice, King added LGBTQ+ issues to her scope of awareness-raising charity work.

Considered by many to be the “mother of modern sports,” Billie Jean King remains active as a coach, commentator and advocate for women’s sports and other social causes. In 2006, the USTA National Tennis Center, home of the U.S. Open, was renamed the Billie Jean King National Tennis Center. During the dedication ceremony, John McEnroe called her “the single most important person in the history of women’s sports.” After reading ALL IN, a thorough and detailed testimony of her passion, perseverance and heart, it’s easy to see why.