But is the successful, single black woman a matter of statistics, or are there other more controversial factors at hand? "Nightline" tackled the phenomenon in a piece originally reported by ABC News’ Linsey Davis in late 2009. The piece. From athletes to activists to writers to filmmakers to curators, these black women are truly Undefeated. Serena Williams waves to the crowd as she leaves the court with the Daphne Akhurst…