In his autobiography, ‘‘Black and White: The Way I See It,’’ Richard Williams describes toughening the girls’ ‘‘skin’’ by bringing ‘‘busloads of kids from the local schools into Compton to surround the courts while Venus and Serena practiced. I had the kids call them every curse word in the English language, including ‘Nigger,’ ’’ he writes. ‘‘I paid them to do it and told them to ‘do their worst.’ ’’ His focus on racism meant that the sisters were engaged in two battles on and off the court.

-- Claudia Rankine