There are many different ways to gauge the greatness of Simone Biles. Icons from different eras testify she is the best gymnast they've ever seen, Nadia Comaneci reckons the difficulty of her routines is comparable to that of her male counterparts, and, last October, the 18-year-old became the first woman to win three consecutive golds in the all-round at the world championships. But, perhaps the most graphic demonstration of her immense powers came in the aftermath of her first title back in 2013.

"I told Vane (team-mate Vanessa Ferrari) that next time we'll have our skin black also so we can win too," said Italy's Carlotta Ferlito who had finished 11th behind the American. Although Ferlito later apologised, an official with the Italian Gymnastics Federation voiced what many of Biles' detractors were actually thinking.

"Carlotta was talking about what she think is the current gymnastics trend," wrote David Ciaralli. "The code of points is opening chances for coloured people, known to be more powerful, and penalising the typical Eastern European elegance, which when gymnastics was more artistic and less acrobatic, allowed Russia and Romania to dominate the field. Is gymnastics suiting coloured features more and more, to the point athletes wish they were black?"

Ambitious routines

When rivals attribute her brilliance to some sort of racial pseudo-science and perceived change in scoring instead of simply admitting she attempts and gracefully pulls off some of the most ambitious routines in the history of the sport, she’s already in their heads. Like Tiger Woods or Michael Jordan in their pomp, she is halfway to victory before the competition even starts.

Against that background, it’s easy to understand why Biles, all 4ft 9in of her, is the hottest of favourites to dominate this summer’s Olympics. Six months out from Rio, the hype is already starting to build even if America has a rather curious relationship with this sport. Every four years the country goes berserk about distaff gymnasts, living and dying with the successes and soap operatic failures of girls that go rapidly from anonymity to national darlings. Then, almost as quickly, everybody tunes out again.

Fame may prove more enduring for Biles, blessed with an effervescent smile, a charming personality, and a Dickensian backstory that will have Hollywood mavens salivating at the prospect of giving it the full cinematic treatment. Born in Columbus, Ohio to a mother who was in and out of rehab battling alcohol and drug addiction, she spent time in foster care before she and her younger sister Adria ending up being legally adopted by her grandparents, Ronnie and Nellie, in Texas.

"She thought she was a little mom in her house," said Nellie Biles. "She made decisions for herself and her sister because this was all they knew."

Shortly after arriving in Houston, her life took another fortuitous turn. When a school field trip to a farm was cancelled due to bad weather, her class was diverted to Bannon’s Gymnastix. There, something in the child clicked. One of the coaches on hand spotted the six-year-old Biles performing a round-off back handspring on a trampoline and saw enough raw talent that the kid arrived home that night with a note asking her parents to contact the club. Two years later, by then a fully-fledged prodigy, she was competing against 16-year-olds and her path was set.

"She just took off," said Aimee Boorman, her coach and the woman who recognised her nascent talent that very first day. "She really had an aptitude to learn new skills. She was kind of a daredevil . . . we knew if we were patient with her, she could learn to do anything."

While Biles and Boorman have tried to keep the teenager’s life as normal as possible, not always easy in a sport notorious for subjecting kids to punitive training regimes and dysfunctional lifestyles, she eventually, reluctantly, had to switch to homeschooling to allow for more time at the gym. Similarly, plans to go to UCLA to pursue a career as a paediatric nurse have been sidelined.

Turned pro

Putting school on hold, she turned pro last summer, became just the third gymnast ever to be signed by

Nike

(after an apparently lucrative bidding war), and seems destined for the type of post-Olympic stardom afforded

Michael Phelps

after Athens. Of course, all that is kind of contingent on what happens in Brazil in August. It’s not just that Biles is expected to win there, it’s that she’s expected to win well, while performing audacious and ground-breaking moves that led one pundit to compare her impact on the sport to that of “the first person in space”.

In competition, on the beam, on the vault or on the floor, Biles is a study of impeccable grace under pressure. She will need to be all that and more as her celebrity grows, especially in a country where the more prurient sections of the media may soon focus on the addict mother with whom she does have a relationship but who will not be travelling to the Olympics.

“It’s not something we bring her into because that would just blow it up and make it bigger,” said Biles. “We’re just trying to keep it small.”

The more she achieves the less chance of succeeding on that score.