Since the ATP computerized ranking was introduced in 1973, 100 players have spent at least one week inside the ATP Top 9. The all-time leader is Roger Federer with 959 weeks, a margin 3% ahead of Novak Djokovic (932 weeks) and Rafael Nadal (904 weeks). 100 players have accumulated 52 or more weeks inside the Top 9, with an average of 228 weeks across all ranked players.