Watch Online Free on Watchseries. If you've attended a women's roller derby bout in its latest incarnation, you've seen it: the love and addiction that drives thousands of women around the globe to don fishnets, stage names and roller skates. The number of female league-skaters in the US is estimated over 20,000, and the first-ever World Cup in 2011 had women around the globe lacing up skates to compete internationally. Narrated by actress/musician 'Juliette Lewis' , Derby Baby takes viewers on a quest to learn why women's roller derby is the fastest growing sport in the world.