Women’s top seeds

SIMONA HALEP (1), Romania

2017 Match Record: 45-17(1 title)

Career Singles Titles: 15 (no majors)

Topspin: Has never advanced beyond the quarterfinals at the Australian Open and, for the last two years, has lost in the first round. Last year, she was beaten by American Shelby Rogers while bothered by a sore knee . ... She was fourthseeded then but comes into this year’s Australian Open with the No. 1 ranking despite still having no Grand Slam singles titles ... Had her equal-best Grand Slam performance at last year’s French Open, losing in the final to Jelena Ostapenko despite being a set and 3-0 up. She lost the 2014 final at Roland Garros to Maria Sharapova . ... Won last week’s Shenzhen Open, beating Katarina Siniakova in the final, to ensure she’d remain the top-ranked player this week.

CAROLINE WOZNIACKI (2), Denmark

2017 Match Record: 60-21 (2 titles)

Career Singles Titles: 27 (no majors)

Topspin: In 2011, made it to the semifinals at Melbourne, losing to Li Na. She lost in the quarterfinals the following year to Kim Clijsters, a defeat which cost Wozniacki her No. 1 ranking . ... Held the top ranking at stages of 2010, 2011 and 2012, without having won a major . ... Is edging closer back to the No. 1 spot, thanks in part to Serena Williams’ long absence, but still hasn’t won that elusive first Grand Slam singles title. Lost in the final of the ASB Classic to Julia Goerges in Auckland, New Zealand, last week before rising to No. 2 in the rankings.

GARBINE MUGURUZA (3), Spain

2017 Match Record: 47-21(2 titles)

Career Singles Titles: 5 (2 majors, 0 Australian Open) Topspin: Coming off one her best seasons, backing up her first major at the French Open in 2016 (beating Serena Williams) with a second major title at Wimbledon in 2017, beating Venus Williams in straight sets to become the first player to defeat both Williams sisters in major singles finals. ... Took over the No. 1 ranking at the U.S. Open despite losing in the fourth round, but held it for only four weeks ... Forced to retire with cramping in her first match of the year at the Brisbane International. Accepted a wild card at the Sydney International but withdrew ahead of her quarterfinal match with a right thigh injury.

ELINA SVITOLINA (4), Ukraine

2017 Match Record: 50-13 (5 titles)

Career Singles Titles: 10 (no majors)

Topspin: Had a breakout season last year, winning five tournaments and reaching a career-high No. 3 ranking in September . ... Started off the new year in fine style with a win at the Brisbane International, ensuring she’d move up two ranking spots to take the fourth seed at the Australian Open … Has never had much success at Melbourne Park, losing in the third round in three of her five past appearances.