People say a good coach never retires! So might be the case with Richard Williams, father of tennis icons Serena and Venus Williams. Richard recently stood on the sidelines as his grandbaby Alexis Olympia Ohanian Jr. tackled bike riding. Serena took to Instagram on Friday to share the sweet moment.“A rare sighting, the one and only G.O.A.T. still motivating,” Serena wrote in the Instagram caption. “King Richard, but I call him daddy.”According to Entertainment Weekly, Richard has steered clear of the spotlight since his 2016 health complications. But the short video shared by his daughter Serena gave insight to his role as a granddad. The clip shows Serena, Alexis and Richard in an outdoor scene. Alexis is practicing her riding skills on her pink-and-white bicycle.As she rides down the sidewalk, Richard records on a cellphone. He offers kind words while Alexis Olympia is plugged into her steady riding. Richard cheers her on saying “Go on, girl, you are the best.”The moment seems to be full circle for Serena, who was trained by her father to be one of tennis’ greatest players. His coaching of both daughters into being top athletes and global celebrities has landed him a biopic called ‘King Richard.’Will Smith will portray the famed father and coach in the upcoming film. He began the physical transformation for the role in February by growing out his beard. The look reflects Richard during Serena and Venus’ early tennis careers in the ’90s. The film will cover that time period as well as how he propelled his daughters into their status with little prior tennis knowledge.Richard started training his daughters as early as four years old. He reportedly wrote and followed a 78-page custom plan to make stars of Venus and Serena.Back in August Serena spoke to Refinery29 and praised her father for “always thinking on a different level.”“There would be no Venus and Serena if it wasn’t for Richard,” Serena said.