The rankings are based on performances on the eight major tours (LPGA, JLPGA, KLPGA, LET, ALPG, Epson Tour, LETAS, CLPGA) over a two-year period. Amateur players are eligible. The system for calculating the rankings is similar to that for the men's Official World Golf Ranking. Players receive points for each good finish on the relevant tours, with the number of points available in each event depending on the strength of the field, as determined by the competitors' existing rankings (when the rankings were introduced rankings were calculated for earlier periods; the first ever set showed notional changes since the previous week). The only exceptions are the five
LPGA majors and all Epson Tour, CLPGA and LETAS events which have a fixed-point allocation, presently 100 points for the majors. Rankings are weighted as to the time elapsed over the two years, making the recent results more important.
Original formula When the rankings were first introduced in February 2006, a player's ranking as calculated in the above description was divided by the number of events played, with a minimum required events of 15 over the previous two years. In addition, players were required to play in a minimum of 15 eligible events over the previous two-year period to be included in the rankings.
Formula revisions On August 2, 2006, the Rolex Rankings Board and Technical Committee announced following its bi-annual meeting two changes to the ranking formula. • The elimination of the minimum event requirement. Players would no longer be required to participate in 15 qualifying events to be included in the rankings and could be included after playing in as few as one qualifying event. This change would also have the effect of permitting amateurs who had played well in one event to be ranked (e.g.,
Morgan Pressel, who finished second in the 2005
U.S. Women's Open, or
Michelle Wie from age 13). • The introduction of a minimum divisor. Where previously a player's point total was divided by the number of events she played over the previous 104 weeks, now the player's point total would be divided by the greater of (i) the number of events played or (ii) 35. Thus, players with 35 or more events over the previous 104 weeks would continue to use the actual number of events played as the divisor, but players with fewer than 35 events would use 35 as the divisor. Many commentators saw the latter change as directed at
Michelle Wie, who at the time was ranked second in the world despite having competed in only 16 women's professional events in the two-year period. However, the chairman of the Rolex Rankings Technical Committee defended the change as one designed to make the women's rankings more comparable to the
Official World Golf Ranking for men, which use a minimum divisor of 40 events. On April 16, 2007, another modification in the formula was introduced. Instead of points being awarded on an accumulated 104-week rolling period, with the points awarded in the most recent 13-week period carrying a higher value, points began to be reduced in 91 equal decrements following week 13 for the remaining 91 weeks of the two-year Rolex Ranking period rather than the seven equal 13-week decrements previously used.{{cite web |title=Modification Announced to Rolex Rankings Calculations |publisher=LPGA ==Criticisms==