Stefanos Tsitsipas looks back on winning the Next Gen ATP Finals and Nitto ATP Finals in back-to-back seasons. SUBSCRIBE: bit.ly/2dj6EhW WEBSITE: atptour.com FACEBOOK: facebook.com/ATPTour TWITTER: twitter.com/ATPTour INSTAGRAM: instagram.com/atptour About the Official ATP Tour YouTube Channel: As the global governing body of men’s professional tennis, the ATP’s mission is to serve tennis. We entertain a billion global fans, showcase the world’s greatest players at the most prestigious tournaments, and inspire the next generation.