CINCINNATI, OH, USA - At the beginning of January few would have pegged Angelique Kerber as the player most likely to overthrow Serena Williams atop the rankings. This number would have dwindled further when she stood match point down against Misaki Doi in the opening round of the Australian Open.
What happened next will go down in tennis folklore, Kerber somehow negotiating her way out of this cul-de-sac and going on to lift her maiden Grand Slam trophy. A wonderfully consistent summer has built on this career momentum, establishing Kerber as a rival to long-time World No.1 Williams at the game's summit.
Victory over Karolina Pliskova in Sunday's final of the Western & Southern Open will not only give her more silverware but also the No.1 ranking. Should she do so, it will end one of the most dominant reigns in WTA history. So to mark the potential changing of the guard, wtatennis.com has picked out some notable numbers...
38,473,935 - Williams' sixth and current spell at the top of the rankings began on February 18, 2013. Since then she has amassed $38,473,935 in prize money - nearly half her career total of $80,899,060.
4,880,887 - Not including her earnings this week, Kerber has already accumulated a career-best $4,880,887 this season.
6,355 - At the start of 2016, then No.10 Kerber trailed Williams by 6,355 points in the rankings.
183 - Of the above total, 183 have come in her latest reign. Williams is spending her 183rd straight week at No.1 (the second-longest streak at No.1 in WTA history after Graf's 186). Her previous longest streak was 57 (between July 8, 2002 and August 10, 2003).
47 - Kerber has already notched up 47 wins this season, a record not matched by any other player on tour. Williams has posted 33.
34 - Thirty-four-year-old Williams is the oldest No.1 in WTA history, a record she first set when returning to No.1 on February 18, 2013
28 - At 28, Kerber would be the oldest first-time No.1. Her closest competition is Jennifer Capriati, who was 25 years and seven months old.
22 - Kerber is bidding to become the 22nd woman to reach the summit of the rankings.
18 - Williams' win-loss record in this latest stint at the summit is a staggering 204-18.
12 - When a 20-year-old Williams reached No.1 for a first time in July 2002 she was the 12th different woman to scale the top of the rankings.
2 - Kerber is hoping to become the second German, after Graf, to be ranked No.1. Other nations to have multiple No.1s are the United States (Chris Evert, Navratilova, Tracy Austin, Monica Seles, Lindsay Davenport, Capriati, Venus Williams, Serena), Serbia/Yugoslavia* (Seles, Ana Ivanovic, Jelena Jankovic), Belgium (Kim Clijsters, Justine Henin) and Russia (Maria Sharapova, Dinara Safina).
* Before her change of citizenship Seles, who was born in the Serbian city of Novi Sad, represented Yugoslavia