Not only did Venus and Serena get behind King Richard, but they were both executive producers, along with their sister, Isha Price. The movie couldn't have been made without their input, along with the stories they provided its writer, Zach Baylin. According to an interview with USA Today, the Williams sisters were insistent the film accurately depict "how loving and kind their father was to them." They had zero interest in adding to any rumors that Richard was a pushy father, focused solely on tennis.

Will Smith, who plays Richard, told USA Today, "He was pushing them to go to church and to get good grades and to be good people. Tennis was fourth or fifth on the list of priorities. He was using tennis to teach them how to survive in this world." Will was equally as determined to paint an accurate picture of Richard. When he tried to take tennis lessons, he learned that Richard didn't really know how to play, therefore Will shouldn't know either. He stopped the lessons right then and there.

Richard also had a sense of humor that didn't stop when it came time to get down to business. One of Venus's favorite stories about her dad is about a time Richard was in a particularly disagreeable meeting with a sports agent. Richard didn't like where it was going, so he farted, quite loudly. This was a regular occurrence when the sisters were younger. About this, Will said, "If it didn't happen for real, you would think it was fake."