Serena Williams will return to No.1 on the WTA Rankings, when they are released on April 24, 2017, when the points from last year’s Porsche Tennis Grand Prix in Stuttgart drop off.

Two-time defending Stuttgart champion Angelique Kerber will have an immediate chance to return to the top spot by reaching the semifinals of this year’s event, which takes place a week later this year due to a shift in the calendar.

As top seed in Stuttgart, Kerber, who has held the No.1 ranking for 25 weeks, will receive a first round bye, so will need to win two matches to overtake Williams.

The WTA Rankings are based on a 52-week, cumulative system with each players singles ranking determined by 16-best results; WTA Finals participants count points earned as the 17th bonus tournament.

For Williams it will be her 317th week at No.1, the third most in WTA Rankings history behind only Stefanie Graf (377) and Martina Navratilova (332).