Overall tennis records – women's singles covers the period 1884 to present.
Before the beginning of the Open era in April 1968, only amateurs were allowed to compete in established tennis tournaments, including the four Grand Slams. Wimbledon, the oldest of the Majors, was founded in 1877, followed by the US Open in 1881, the French Open in 1891, and the Australian Open in 1905. Beginning in 1905 and continuing to the present day, all four majors have been played yearly, with the exception of the two World Wars and 1986 for the Australian Open. The Australian Open is the 1st Major of the year (January), followed by the French Open (May–June), Wimbledon (June–July), and US Open (August–September). There was no prize money and players were compensated for travel expenses only. A player who wins all four current major tournaments, as a single or as part of a doubles team, in the same calendar year is said to have achieved the "Grand Slam". If the player wins all four consecutively, but not in the same calendar year, it is called a "Non-Calendar Year Grand Slam". Winning all four at some point in a career, even if not consecutively, is referred to as a "Career Grand Slam". Winning the four Majors and a gold medal in tennis at the Summer Olympics has been called a "Golden Slam" since 1988. Winning all four plus gold at some point in a career, even if not consecutively, is referred to as a "Career Golden Slam". Winning the Year-End Championship also having won a Golden Slam is referred to as a "Super Slam". Winning the four Majors in all three disciplines a player is eligible for – singles, doubles, and mixed doubles – is considered winning a "boxed set" of Grand Slam titles. The current Grand Slams are the four most prestigious tournaments in the world held every year, they are distinguished by participation from almost every top player and by their two-week duration, 128-player draw in women's singles. It's extremely rare for a player to win all four events, "the Grand Slam", in one calendar year. This was only achieved three times since 1888 by Maureen Connolly, Margaret Court, and Steffi Graf, the latter of whom stands alone in winning the "Golden Slam".
These are some of the important records since the start of women's tennis in 1884.
** Not all sources agree with one of Wills' losses. She did not play two matches because of appendicitis, causing her to miss the 1926 Wimbledon Championships. Wimbledon did not assign a loss to her or a win to her opponent. The other tournament gave her a loss instead of a default to her and a walkover to her opponent, neither of which count as a loss or a win. It is unknown why the tournament chose to assign a loss to her. Taking these facts into consideration, her adjusted win percentage would be 125–3 = 97.66%.
Note that the figures below represent career winning percentages of players that are retired (regular font) as well as current active players (boldface). The latter are subject to change and do not reflect the final figure.
Notes: 1883 –1920 rankings are more variable in nature because of limited sourcing from 1921 onwards more recent rankings are much better sourced are shown here World number 1 women tennis players. Before the open era of tennis arrived in 1968, rankings for amateur players were generally compiled only for a full year of play. Professional players were ranked by journalists, promoters, and players' associations usually at the end of the year. Even for amateurs, however, there was no single official overall ranking that encompassed the entire world. Instead, nation rankings were done by the national tennis association of each country, and world rankings were the preserve of tennis journalists. It was only with the introduction of computerized rankings in the open era that rankings were issued more frequently than once yearly. Even the end-of-year amateur rankings issued by official organizations such as the United States Lawn Tennis Association were based on judgments made by men and women and not on mathematical formulas assigning points for wins or losses.