WTA rankings
The WTA rankings are the ratings defined by the Women's Tennis Association, introduced in November 1975. Ranking method. The WTA rankings are based on a rolling 52-week, cumulative system. A player's ranking is determined by her results at a maximum of 16 tournaments for singles and 11 for doubles and points are awarded based on how far a player advances in a tournament. The basis for calculating a player's ranking are those tournaments that yield the highest ranking points during the rolling 52-week period with the condition that they must include points from  the 4 Grand Slams, the 4 Premier Mandatory tournaments and the WTA Finals. In addition, for Top 20 players, their best two results at Premier 5 tournaments will also count. Up until 2016, the WTA also distributed ranking points, for singles players only, who competed at the Summer Olympics. However, this has since been discontinued. The computer that calculates the ranking is nicknamed "Medusa". In order to appear on the WTA rankings, players must earn ranking points in at least three tournaments, or a minimum of 10 singles ranking points or 10 doubles ranking points in one or more tournaments . The points distribution for tournaments in 2021 is shown below. Points earned in 2013 were a little different in some cases and retained their value until they expired after 52 weeks. S = singles players, D = doubles teams, Q = qualification players. <nowiki>*</nowiki> Assumes undefeated Round Robin match record. "+H" indicates that Hospitality is provided. Note that if a player or team receives one or more byes and then loses their first match of the tournament, they will only receive points for the first round of that tournament. For example, if a player receives a bye  in R64 and then loses her match in R32, she will only receive points for R64 despite having advanced (via bye) to R32. Similarly, if a player or team withdraws from their first match after receiving a bye, they will not be awarded any points for that tournament. In ITF tournaments, the main draw is normally 32 for singles and 16 for doubles. Losers in the first round of doubles will receive points equal to that shown in the R32 column above. For subsequent rounds (quarter-finals onwards) the points are the same as for singles. Number one ranked players . The following is a chronological list of players who have achieved the number one position in singles since the WTA began producing computerized rankings on November 3, 1975: "Last update: " Year-end number one players. The year-end number one player is the player at the head of the WTA rankings following the completion of the final tournament of the calendar year. Players with highest career rank 2–5. The following is a list of singles players who were ranked world No. 5 or higher but not No. 1 since Nov 3, 1975: Players with highest career rank 6–10. The following  is a list of players who were ranked world No. 6 to No.10 in the period since the 1975 introduction of the WTA rankings. Consecutive weeks in the Top 10. The below lists the singles players with the most consecutive weeks in the Top 10 of the WTA World rankings: "Last update: "