"Mack Wrestles" is an ESPN 30 for 30 short that premiered at the SXSW Film Festival in March.

When I first saw the news story about Mack Beggs, a transgender boy wrestling in Texas, in February 2017, I'd wanted to write about Texas for months. The University Interscholastic League there had approved a policy the previous year that explicitly restricted the ability of transgender high school students to compete in athletics. As with most UIL policy amendments, this one came as a ballot measure sent to each of the state's superintendents. It went into effect on Aug. 1, 2016, with the approval of 95% of superintendents.

As I read the story, I knew it would be news. A transgender boy who was medically transitioning had just qualified to wrestle in the girls' state tournament because his opponent had forfeited in protest in the championship match of the district competition. In Texas. Weeks after a bill similar to North Carolina's HB2 -- the controversial "bathroom bill" -- had been filed in Austin.

The scene, predictably, was chaotic. Cameras followed Mack everywhere he went at the state tournament. Reporters camped out on his lawn. Morning shows called him. Even "The Ellen DeGeneres Show" wanted to talk to him, according to his grandmother, Nancy. And Mack won.

They are the champions For more on Mack Beggs, read They are the champions, a story that reveals the struggle of two young transgender athletes to compete in the sports they love.

While in high school, he would go on to win back-to-back 6A 110-pound girls wrestling state championships, posting a 92-0 record over his final two seasons. And on Sunday, ESPN will debut a sliver of his story in "Mack Wrestles," a 30 for 30 short that captures the end of Mack's time in high school and his preparation for college. The film, which I helped produce, is the culmination of three years of this story grabbing me by the shoulders. It's the kind of gift that I seem to never stop opening.

What drew me to Mack's story was the humanity of it. He's just a kid from Texas who loves to wrestle. He's also transgender. After coming out to his family, he socially transitioned his freshman year of high school and began hormone replacement therapy the fall of his sophomore year. The policy in Texas determines sex for the purposes of sports by birth certificate. Since Mack was assigned female at birth, he had to compete in the girls' category. He has since changed his birth certificate.

"Mack Wrestles" co-director Taylor Hess was also captivated by Mack's human story. "I played high school sports," Hess says. "I wasn't a state champion like Mack, but I relate to sports being a way that we express ourselves when we're young. It's a way we can find ourselves and bond with people our own age."

There's been a lot written in recent weeks about the decline in sports participation among today's youth, the demands on the attention of kids -- hello, Fortnite -- and the increasing expense of sports. But for LGBTQ youth, the lack of participation is more fundamental. Sports simply aren't welcoming.

According to a 2018 report from the Human Rights Campaign, while 68% of non-LGBTQ youth participate in school sports, just 24% of LGBTQ do. That same report revealed that 82% of teenage transgender athletes were not out to their coaches. Research from the Gay, Lesbian, and Straight Education Network showed that 11.3% of students reported being steered away from sports by teachers and staff specifically because of their LGBTQ identity.

"The fact right now is that LGBTQ youth do not have equal access to [athletic] environments," says GLSEN executive director Eliza Byard. "Our research indicates that they would feel more comfortable talking to a cop than they would to a coach."

A two-time high school wrestling champion, Mack Beggs went 92-0 in his final two seasons on the mat. Richard Messina for ESPN

Mack often glosses over the difficulties of his high school career, but while in Texas reporting for ESPN The Magazine, I could hear the kids in the stands talking about him. It wasn't kind. This was a year after his first title, and in some ways the atmosphere had worsened since then. When he won his second championship in 2018, the boos rang louder than the cheers.

Mack's experience mirrors those of other transgender athletes. In Connecticut, two transgender girls -- Andraya Yearwood and Terry Miller -- are at the center of a controversy resulting from a Connecticut Interscholastic Athletic Conference policy that allows transgender athletes to compete on the teams that reflect their gender identity without legal or medical intervention. Sixteen states and Washington, D.C., have similar policies. Most people can't name a single transgender athlete competing in those states.

Yearwood and Miller have been competing in girls' track and field for multiple years, but every time one of them wins, the outrage gets piled on. In June, the Alliance Defending Freedom -- co-founded by evangelical leader James Dobson -- filed a Title IX complaint, challenging the legality of the CIAC's trans-inclusive policy. The Department of Education has said the Office for Civil Rights will investigate the complaint.

When I started playing high school basketball 15 years ago, I was just a kid in rural Indiana trying to figure out how I fit into the world. I knew I was attracted to women but wasn't ready to admit that to myself, let alone talk about it. I didn't quite know what to do about my gender. Nothing in my vocabulary quite fit how I felt, but I knew that I really hated wearing a school-mandated kilt every day. It wouldn't be until almost a decade later that I would be able to claim a label that worked for me: non-binary.

I don't know that if I were 14 years old today I would identify as non-binary, or if that would change any part of my athletic experience. But young people today have access to more vocabulary and options for how they want to self-identify than ever before. A CDC study published in January said that 1.8% of high school students are transgender.

We have built sport on the fundamental belief that life happens in a binary way -- male and female; men and women. That belief continues to be challenged by the existence of transgender, non-binary, and gender-non-conforming people. Gender is messy, no matter how badly sport wants us to believe that it's not.

In the final scene of the film -- no spoilers, I promise -- Mack is at college. This year, he's a sophomore at Life University and will be wrestling this season on the men's team. He took last year off to recuperate from top surgery but continued to train. "I was really mad that I couldn't do as much as I wanted to," Mack says.

Mack says he can't wait to wrestle this season and get back on the mat. He's an athlete, after all. It's where he belongs.