The Battle for No.1 kicked off right out of the gates in January and came down to the wire in the final week of the season in Singapore. In a year that saw Angelique Kerber begin at No.1 and Serena Williams return to the WTA's penthouse after winning her record-breaking 23rd major at the Australian, 2017 was also the first time three new No.1s were crowned in a single season. This is just the second time since the inception of computer rankings in 1975, that five different players held the top spot over the course of a year.
Karolina Pliskova became the first woman to represent the Czech Republic to become the 23rd WTA No.1 after Wimbledon. Garbiñe Muguruza became the 24th woman and second Spanish woman to hold No.1 after the US Open.
But it was Simona Halep who edged out the field in the end, becoming the 25th player and first Romanian to hold the WTA No.1 ranking after the China Open. She went on to hold her lead through Singapore to become the 13th player to finish the season at No.1. The last time a season saw even two new No.1s crowned was 2008, when Ana Ivanovic and Jelena Jankovic made their No.1 debuts.
The trend of new No.1s was not confined to the singles game. Five women held the No.1 doubles ranking as well in 2017, with three new No.1s crowned. Bethanie Mattek-Sands overtook the No.1 spot from Sania Mirza, after the two teamed up in the first week of the season and won Brisbane. Mattek-Sands' good friend and partner Lucie Safarova moved to No.1 after Cincinnati, putting the Czech flag atop both the singles and doubles rankings for the first time.
And Martina Hingis finished off her incredible career with one of her best seasons, rising to No.1 with Chan Yung-jan to cap off a wild season of doubles. Chan became the second woman from Chinese Taipei to hold the No.1 doubles spot.
WEEKS AS WTA WORLD NO.1 IN 2017
18 weeks: Angelique Kerber (GER)
10 weeks: Serena Williams (USA)
12 weeks: Simona Halep (ROU)
8 weeks: Karolina Pliskova (CZE)
4 weeks: Garbiñe Muguruza (ESP)
WTA YEAR-END NO.1s:
Chris Evert: 1975, 1976, 1977, 1980, 1981
Martina Navratilova: 1978, 1979, 1982, 1983, 1984, 1985, 1986
Stefanie Graf: 1987, 1988, 1989, 1990, 1993, 1994, 1995 (shared with Seles), 1996
Monica Seles: 1991, 1992, 1995 (shared with Graf)
Martina Hingis: 1997, 1999, 2000
Lindsay Davenport: 1998, 2001, 2004, 2005
Serena Williams: 2002, 2009, 2013, 2014, 2015
Justine Henin: 2003, 2006, 2007
Jelena Jankovic: 2008
Caroline Wozniacki: 2010, 2011
Victoria Azarenka: 2012
Angelique Kerber: 2016
Simona Halep: 2017