There was talk all weekend during the 2017 ShopRite LPGA Classic about how Lydia Ko was going to lose the No. 1 spot in the Rolex Rankings after the weekend in Atlantic City. It was just a matter of who would take over for Ko: So Yeon Ryu, who was in the field, or Ariya Jutanugarn, who wasn't.
When Ryu missed the cut, the projection put forth by the Rolex Rankings team made it clear that Jutanugarn would become the new world No. 1.
However, the updated ranking is out, and Lydia Ko is still the top-ranked player. Why?
As it turns out, the Rolex Rankings projections wrong. From the Rolex Rankings:
When running the projections, the tool used the date on which the projections were run (June 4), rather than the date when the rankings would be released (June 5). Thus when projections were run last week, they included the 2015 Manulife LPGA Classic in the event count for both Lydia Ko (51 events) and Ariya Jutanugarn (58 events). When the Rankings were run today, that event correctly dropped from the Rankings’ 104-week cycle and reduced the total number of events for both players by one (Ko – 50 events; Jutanugarn 57 events) which resulted in average world ranking points of 8.37 for Ko and 8.36 for Jutanugarn.
In other words, Ko remains No. 1 for one more week by 0.01 average points, which is the measure by which the rolling 104-week ranking system decides the Rolex Rankings, as a measure of total points earn (deprecated over time in equal installments after 13 weeks) divided by events played in that stretch.