List of ATP Number 1 Ranked Singles Players

List Of ATP Number 1 Ranked Singles Players

The ATP Rankings are the Association of Tennis Professionals' (ATP) merit-based method for determining the rankings in men's tennis. The top-ranked player is the player who, over the previous 52 weeks, has garnered the most ATP ranking points. Points are awarded based on how far a player advances in tournaments and the category of those tournaments. The ATP has used a computerized system for determining the rankings since 23 August 1973. An updated rankings list is released at the beginning of each week.

Since the introduction of the ATP rankings the method used to calculate a player's ranking points has changed several times. As of 2011, the rankings are calculated by totaling the points a player wins in his best eighteen tournaments, subject to certain restrictions. For top players the counting tournaments are the four Grand Slam tournaments, the eight mandatory ATP World Tour Masters 1000 tournaments, the player's best four eligible ATP World Tour 500 series tournaments (the non-mandatory ATP Masters 1000 event in Monte Carlo may be substituted for one of these), and his best two results from ATP World Tour 250 series. Lower-ranked players who are not eligible for some or all of the top tournaments may include additional ATP 500 and ATP 250 events, and also ATP Challenger Series, and Futures Series tournaments. The ranking points of players who qualify for the year-end ATP World Tour Finals also include any points gained at that tournament, increasing their counting tournament total to nineteen.

Since 1973, 25 men have been ranked number 1 by the ATP. Roger Federer holds the record for the most total weeks at number 1 (302) and most consecutive weeks at number 1 (237). Pete Sampras holds the record for the most year-end number 1 (six, all consecutive). Two players, Ivan Lendl and Marcelo Ríos, have reached number 1 without previously having won a Grand Slam tournament. Lendl reached number 1 on February 21, 1983, but did not win his first Grand Slam title until the 1984 French Open. Rios reached number 1 on March 30, 1998 and is the only number 1 player who never won a Grand Slam singles title. Patrick Rafter spent the fewest weeks at number 1 (one week). Lleyton Hewitt is both the youngest world number 1 (20 years, 268 days) and youngest year-end number 1, while Ivan Lendl is the oldest year-end number 1 (29 years, 299 days). Andre Agassi is the oldest number 1 (33 years, 131 days).