How well do the players know their tennis history? Some of the best ATP Tour doubles teams are challenged to name all the teams to have finished year-end World No. 1... in order! 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.