The Pepperstone ATP rankings are the Association of Tennis Professionals' (ATP) merit-based system 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 ranking points on the ATP Tour. 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 August 23, 1973. Starting in 1979, an updated rankings list is released at the beginning of each week. Since 1973, 28 players have been ranked No. 1 by the ATP, of which 17 have been year-end No. 1.
Since the introduction of the rankings, the method used to calculate a player's ranking points has changed several times. As of 2019, 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 Masters tournaments, the player's best four eligible ATP Tour 500 tournaments (the non-mandatory ATP Masters 1000 event in [[Monte-Carlo and his best two results from ATP Tour 250 tournaments. 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 Tour, and ITF Men's Circuit tournaments. Players who qualify for the year-end ATP Finals also include any points gained from the tournament in his total, increasing the number of tournaments counted to 19.
Novak Djokovic has spent the most weeks as world No. 1, a record total 380 weeks. Roger Federer has the record of 237 consecutive weeks at No. 1. Djokovic also holds the record for the most year-end No. 1 rankings, achieving the feat for seven years (including the pandemic-shortened season).Pete Sampras held the year-end No. 1 title for a record six consecutive years, while Djokovic held the year-end No. 1 ranking for consecutive years three times.
Carlos Alcaraz is both the youngest world No. 1 (19 years, 4 months), and the youngest year-end No. 1 (19 years, 7 months). Federer is the oldest No. 1 (36 years, 10 months), while Djokovic is the oldest year-end No. 1 (34 years, 7 months).
Federer is the player with the longest time span (14 years) between his first and most recent dates (February 2004 – June 2018) at No. 1, while Rafael Nadal has the longest time span (11 years) between his first and last (2008–2019) year-end No. 1 ranking.
Two players, Ivan Lendl and Marcelo Ríos, have reached No. 1 without previously having won a major singles title. Lendl reached No. 1 on February 21, 1983, but did not win his first Grand Slam title until the 1984 French Open. Ríos reached No. 1 on March 30, 1998, but retired without ever having won a Grand Slam title, making him the only No. 1 player with that distinction.
Federer holds the record of wire-to-wire No. 1 for three consecutive calendar years. Since 1973 when the ATP rankings started, there have been 13 years in which one player held the top spot for the entire year: Jimmy Connors in 1975, 1976, and 1978; Lendl in 1986 and 1987; Pete Sampras in 1994 and 1997; Hewitt in 2002; Federer in 2005, 2006, and 2007; and Djokovic in 2015 and 2021. In contrast, 1999 saw five players hold the No. 1 ranking (the most in any single year): Sampras, Carlos Moyá, Yevgeny Kafelnikov, Andre Agassi, and Patrick Rafter.
Prior to 2009, Federer accumulated the most year-end ATP ranking points in any season, with 8,370 points in 2006. Since the introduction of a new point scale for the ATP rankings from 2009, Djokovic achieved the same feat with 16,585 ranking points in 2015 season. Djokovic also holds the record of 16,950 ranking points on 6 June 2016, the most ATP points ever accumulated by any player.
John McEnroe held the No. 1 ranking a record 14 times, and Sampras is the only other player to have held it 10 or more times, with 11 stints. Rafter spent the least time at number 1 (one week).
Novak Djokovic holds an all-time record of seven year-end No. 1 rankings.
Pete Sampras finished a six consecutive years as world No. 1 in the 1990s.
John McEnroe finished as the year-end No. 1 for four consecutive years in the 1980s.
The ATP year-end No. 1 (ATP Player of the Year), in recent decades, has been determined as the player who ends the year as world No. 1 in the ATP rankings. Prior to the early 1990s this was not always the case, in some instances the "ATP Player of the Year" and the Year-end No. 1 in the rankings were different players. Novak Djokovic holds the ATP record of seven year-end No. 1 rankings. 18 players have achieved the year-end No. 1 ranking, four them (Lendl, Federer, Djokovic, Nadal) have done so in non-consecutive years. Six players have stayed at No. 1 in the ATP rankings every week of a calendar year. Connors and Federer have done so for three calendar years, Connors non-consecutively and Federer consecutively.
* Player was ranked No. 1 throughout the calendar year.
^ abcdefghi"Hewitt jubilant as world's No. 1". The Age. November 15, 2002. Retrieved September 6, 2012. Only five other players – Stefan Edberg (1990–91), Ivan Lendl (1985–87), John McEnroe (1981–84), Bjorn Borg (1979–80) and Jimmy Connors (1974–78) – have achieved the mighty feat.
^ abcFord, Bonnie D. (April 9, 2010). "Tennis still imbued in Lendl's blood". ESPN. ESPN Internet Ventures. Retrieved September 6, 2012. In 1988, [Wilander] won a five-set endurance contest, breaking a six-match losing streak to Lendl. The win interrupted Lendl's three-year reign as world No. 1...
^Wilansky, Matt (August 31, 2006). "Inside the numbers". ESPN. ESPN Internet Ventures. Retrieved September 5, 2012. [I]n 1999 he won the French Open title, the only Major that had eluded him. He finished the year ranked No. 1 in the world for the first and only time in his career.