Defending champion Barbora Strycova trails Kirsten Flipkens 2-3 overall in a rivalry dating back to 2006. The Czech won that first meeting in the first round of the Joué-les-Tours ITF $50,000 event 6-1, 3-6, 7-6(4) - their only indoor hard court match to date - as well as their most recent, in the 2014 Birmingham quarterfinals, 6-4, 6-2. In between, Flipkens won their tilts in Deauville in 2007, the 2012 US Open and Tokyo 2013.
The all-German rivalry between No.1 seed Julia Goerges and Andrea Petkovic is all square at 2-2. Both of Goerges' victories have been three-setters - 0-6, 7-5, 6-1 in Sydney qualifying in 2008 and 5-7, 6-4, 7-5 in this year's Washington semifinals - while Petkovic has won twice in straight sets, in the second round of Nurnberg 2013 and the first round of Cincinnati 2015.
No.2 seed Kiki Bertens is the only player in the field who still has a mathematical chance of qualifying for the BNP Paribas WTA Finals Singapore presented by SC Global. The brand new World No.10 needs to reach the quarterfinals to add points; her first opponent, wildcard Barbara Haas, comes into the tournament with a 1-8 record in WTA main draws, her sole victory coming via a third-set tiebreak over Basak Eraydin in Gstaad last year.
No.9 seed Katerina Siniakova has split two previous meetings with Ekaterina Alexandrova, both on clay over three sets. The Russian took their first encounter in the first round of Roland Garros last year 6-4, 2-6, 6-2, and Siniakova gained revenge in the second round of Prague this year 6-4, 3-6, 6-3.
Alison Van Uytvanck and qualifier Anna Karolina Schmiedlova's rivalry is tied at two apiece, with all four matches taking place in 2015. The Slovak took their only indoor hard court encounter in the Katowice semifinals 6-4, 6-1.
Vera Lapko will seek to make her third consecutive WTA quarterfinal against No.6 seed Anastasia Pavlyuchenkova, having reached that stage at both Guangzhou and Tashkent.
ORDER OF PLAY (all courts start 12 noon)
Kirsten FLIPKENS (BEL) vs Barbora STRYCOVA (CZE) 
Vera LAPKO (BLR) vs Anastasia PAVLYUCHENKOVA (RUS) 
Not before 4pm
[WC] Barbara HAAS (AUT) vs Kiki BERTENS (NED) 
Not before 6.30pm
Julia GOERGES (GER)  vs [WC] Andrea PETKOVIC (GER)
Camila GIORGI (ITA)  vs [Q] Jil TEICHMANN (SUI)
Katerina SINIAKOVA (CZE)  vs [Q] Ekaterina ALEXANDROVA (RUS)
Alison VAN UYTVANCK (BEL) vs [Q] Anna Karolina SCHMIEDLOVA (SVK)
[WC] Mavie OSTERREICHER (AUT) / Nadja RAMSKOGLER (AUT) vs [WC] Melanie KLAFFNER (AUT) / Viktoria KUZMOVA (SVK)
Vera LAPKO (BLR) / Mandy MINELLA (LUX) vs Kirsten FLIPKENS (BEL) / Johanna LARSSON (SWE) 
Nicola GEUER (GER) / Chantal SKAMLOVA (SVK) vs Lyudmyla KICHENOK (UKR) / Katarina SREBOTNIK (SLO)