The ATP Challenger Tour is a series of international men's professional tennis tournaments. It was founded in 1976 as a replacement for the ILTF Satellite Circuit as the second tier of tennis. The Challenger Tour events are the second-highest tier of tennis competition, behind the ATP Tour and ahead of the Men's World Tennis Tour tournaments. The ATP Challenger Tour is administered by the Association of Tennis Professionals (ATP). Players who succeed on the ATP Challenger Tour earn sufficient ranking points to enter the main or qualifying draws at ATP Tour tournaments. Players on the Challenger Tour are typically young players looking to advance their careers, those who fail to qualify for ATP events, or former ATP Tour players looking to return to the top tour.