Red Group
SIMONA HALEP (ROM)
Age: 24
Height: 1.68m
Titles this year: 3 (Shenzhen, Dubai, Indian Wells)
Best Grand Slam result this year: US Open semi-finals
WTA Finals appearances: 2
Fun fact: Idolises Belgian former world No. 1 Justin Henin
Twitter followers: 33, 582
Head-to-head
Maria Sharapova: 0-5
Agnieszka Radwanska: 4-4
Flavia Pennetta: 1-4
MARIA SHARAPOVA (RUS)
Age: 28
Height: 1.88m
Titles this year: 2 (Brisbane, Rome)
Best Grand Slam result this year: Australian Open final
WTA Finals appearances: 7
Fun fact: Last year, she became the first tennis player, male or female, to cross 15 million fans on Facebook.
Twitter followers: 1.86 million
Head-to-head
Simona Halep: 5-0
Agnieszka Radwanska: 12-2
Flavia Pennetta: 2-3
AGNIESZKA RADWANSKA (POL)
Age: 26
Height: 1.73m
Titles this year: 2 (Pan Pacific Tokyo, Tianjin)
Best Grand Slam result this year: Wimbledon semi-finals
WTA Finals appearances: 7
Fun fact: Nicknamed "Ninja" for her crafty skills on court
Twitter followers: 204,412
Head-to-head
Simona Halep: 4-4
Maria Sharapova: 2-12
Flavia Pennetta: 5-3
FLAVIA PENNETTA (ITA)
Age: 33
Height: 1.72m
Titles this year: US Open
Best Grand Slam result this year: US Open champion
WTA Finals appearance: 1
Fun fact: She is engaged to fellow Italian and tennis player Fabio Fognini, ranked No. 22 on the ATP Tour. They are reportedly getting married next June.
Twitter followers: 256,608
Head-to-head
Simona Halep: 4-1
Maria Sharapova: 3-2
Agnieszka Radwanska: 3-5
White Group
GARBINE MUGURUZA (ESP)
Age: 22
Height: 1.82m
Titles this year: 1 (China Open)
Best Grand Slam result this year: Wimbledon final
WTA Finals appearance: 1
Fun fact: Enjoys cooking, baking and dancing.
Twitter followers: 105,072
Head-to-head
Petra Kvitova: 0-0
Angelique Kerber: 3-3
Lucie Safarova: 0-1
PETRA KVITOVA (CZE)
Age: 25
Height: 1.82m
Titles this year: 3 (Sydney, Madrid, New Haven)
Best Grand Slam result this year: US Open quarter-finals
WTA Finals appearance: 5
Fun fact: Won the 2011 edition of the Finals, when it was called the WTA Championships, on her debut.
Twitter followers: 269,904
Head-to-head
Garbine Muguruza: 0-0
Angelique Kerber: 4-2
Lucie Safarova: 7-0
ANGELIQUE KERBER (GER)
Age: 27
Height: 1.73m
Titles this year: 4 (Charleston, Stuttgart, Birmingham, Stanford)
Best Grand Slam result this year: 3rd round at French Open, Wimbledon and US Open
WTA Finals appearance: 3
Fun fact: Trained with 22-time Grand Slam winner and countrywoman Steffi Graf this year, a short stint she credits for a turnaround in her season.
Twitter followers: 139,507
Head-to-head
Garbine Muguruza: 3-3
Petra Kvitova: 2-4
Lucie Safarova: 1-1
LUCIE SAFAROVA (CZE)
Age: 28
Height: 1.77m
Titles this year: 1 (Doha)
Best Grand Slam result this year: French Open final
WTA Finals appearance: 1
Fun fact: Like Muguruza, Safarova will be playing in both singles and doubles.
Twitter followers: 24,527
Head-to-head
Garbine Muguruza: 1-0
Petra Kvitova: 0-7
Angelique Kerber: 1-1
