There were moments during the production of “King Richard” that Isha Price was so struck by the slight stoop in the posture of actor Will Smith and his distinctive Shreveport, La., dialect that she almost called him “Daddy.”

That, after all, was what she and her four sisters, including younger siblings Venus and Serena, called their father, Richard Williams. And because Smith, who portrays Williams, never slipped out of character while on set, he addressed Price as “Miss Isha” each time they spoke because that’s what her father called her.

“It was surreal. He was committed to doing an unbelievable, authentic job,” said Price, 46, who as an executive producer on the film served as an on-set adviser to director Reinaldo Marcus Green and the cast.

A pledge of authenticity was a requisite, Price explained in a recent interview, before the family agreed to give its blessing to the film, which is in theaters and available on HBO Max.

The Williams family had been pitched countless book and film projects over the years by authors and artists eager to tell the story of how two Black sisters rose from the public parks of Compton, Calif., to reach world No. 1, claim 30 Grand Slam titles between them and revolutionize women’s tennis in the process.

Granting such license isn’t easy, noted Price, who is a lawyer. But after an initial reading of Zach Baylin’s script at the urging of a former William Morris Endeavor executive, she agreed to meet the producer and screenwriter and came away impressed.

Richard Williams trains his two daughters, Venus and Serena, on tennis courts in Compton, Calif., with determined commitment to their skills and future. (Warner Bros. Pictures)

“Their willingness and desire to get it right, and to understand, was really critically important,” Price said. “That is what I took back to my family and said, ‘This is an opportunity for us to participate and tell a bit of our story our way.’

“People are complicated, and they’re nuanced,” she added. “They don’t always make the right decision, and they don’t always have the answer. And that’s okay.”

The result is “King Richard,” which chronicles one of the more stunning achievements in sports history: how Richard Williams, with his wife, Oracene Price, developed their two younger daughters into world champions largely by following a script and a faith of their own.

The film spans Venus’s and Serena’s early childhoods, opening with their father drilling them daily, rain or shine, on Compton’s rutted public courts, and closing with Venus’s pro debut in 1994, at 14.

It isn’t so much a dissection of the 85-page blueprint Williams wrote for building tennis champions before his youngest daughters were born as it is a celebration of the values at the core of his champion-building philosophy: love, sacrifice and unrelenting belief.

“In the end, it ends up being a love letter of sorts — a complicated one — to my dad,” said Price, who is joined as an executive producer on the film by Venus and Serena. “He wasn’t perfect, but he was who he was. And everything he did was coming from the best possible place.”

Throughout the film, Williams’s primary drive is to protect.

The threat he sought to shield his daughters from wasn’t just the gun violence in Compton, which ultimately led to the death of the eldest sibling, Yetunde, in 2003. Williams also shields them from threats within the sport as Venus rises up the ranks — skeptical journalists whose questions sowed doubt; coaches who robbed her joy; corporate sponsors who lowballed her worth; and myriad ways, subtle and overt, in which the tennis establishment signaled that a Black family didn’t belong in its country clubs and elite academies.

At nearly every turn, Williams’s refusal to follow convention proved prescient, including yanking Venus from the junior circuit, repelled by what he viewed as emotionally abusive tennis parents.

“He was a man who was willing to fight and do whatever it is he had to do to ensure the success of his daughters,” Price said. “He came across as this crazy guy who was always yelling at people, but that is not who he was. He was always super loving toward us. No matter what happened outside in the world, in our house, it was, ‘Love you, Daddy!’ And he loved us. That is not anything we ever had to doubt — that we had a person that would fight for us, no matter what.”

As production of the film got underway, Price was charged by her family to be their voice on the set. She shared little-known anecdotes with the screenwriter and director, and she conveyed nuances of each family member to the cast.

In the case of Saniyya Sidney, who portrays Venus, Price emphasized the regal bearing that her sister had, even as a preteen.

“I’d say: ‘You’ve got to lift that head up, girl! Venus did not walk with her head down at all!’ ” Price recounted. “Her carriage has always been very royal.”

Smith, who packed on roughly 20 pounds for the role, peppered Price with questions such as: “How would your dad have responded to . . . ? How would he have said this?”

Aunjanue Ellis, who portrays Oracene, had similar questions about the mother’s less voluble but formidable demeanor.

“My mom wanted to make sure we displayed in the film the good, bad or indifferent,” Price said. “Families go through stuff. Parents don’t always get along. Her biggest thing was: It has to be real. It has to be true.”

“King Richard” has been well received at film festivals and advance screenings, including three in Washington, where the family has strong ties.

Price attended the Nov. 5 screening at the Southeast Tennis and Learning Center in Ward 8, which was preceded by a clinic for 40 local youngsters and included the donation of $10,000 of equipment from Wilson, as well as a $15,000 donation to the Yetunde Price Resource Center in Compton.

The SETLC was founded by Cora Masters Barry, a longtime friend of the Williams family. Venus and Serena attended its 2001 opening, and their niece Justus Bobbitt, who attended Howard, is the center’s director.

The U.S. Tennis Association Foundation and Warner Bros. hosted a Nov. 10 screening in downtown Washington attended by youngsters enrolled in National Junior Tennis and Learning chapters in the area. Among them were two pairs of sisters who train at College Park’s Junior Tennis Champions Center: Lauryn and Camille Hall and Ameera and Aqeela Malik.

Afterward, the Halls marveled at the confidence Venus and Serena showed so early in their careers. Lauryn, 18, who has committed to Morgan State, said she appreciated Williams’s effort to preserve the sisters’ childhood, taking them to Disney World in one scene to break up the monotony of training.

The Maliks said they were shocked to learn that the Williams family had dealt with gangs in their early years, and it gave them a deeper appreciation of what they overcame. But they instantly related to the powerful bond between the sisters.

“Off the court, we care for each other,” said Ameera, 17. “But in matches, there is no mercy.”

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