The Association of Tennis Professionals (ATP) World Tour is the number one tier tennis tour for men's tennis competition. The 2011 ATP World Tour calendar cosists of Grand Slam tournaments (organised by the International Tennis Federation (ITF)), the ATP World Tour Masters 1000, the ATP World Tour 500 series, the ATP World Tour 250 series, the ATP World Team Championship, the Davis Cup (organized by the ITF), and the ATP World Tour Finals. Also included in the 2011 calendar is the Hopman Cup, which does not distribute ranking points, and is organised by the ITF.