The women's No. 1 ranking is genuinely in play for the first time in months. Elena Rybakina begins the tournament 434 points behind Aryna Sabalenka, close enough that a deep run and an early defeat for the champion would settle it.
Iga Swiatek and Coco Gauff have their own routes to the top, Gauff arriving on the back of a title in Cincinnati and the confidence that comes with it.
Sabalenka's own recent form has wobbled, which is what turns an arithmetic curiosity into a real race. All three challengers are in different quarters, so the ranking question is likely to survive into the second week.
Summarised by TennisArena from reporting by Sports Illustrated — https://www.si.com/onsi/serve/news/ranking-top-5-us-open-storylines-heading-into-new-york-01m0xb12k9v1