The Nancy Richey Group reaches its conclusion on Day 5 of the WTA Finals, with three players competing for one remaining semifinal place. No.3 seed Jessica Pegula takes on No.7 seed Aryna Sabalenka, before No.2 seed Ons Jabeur faces No.5 seed Maria Sakkari.
Sakkari is already guaranteed of a semifinal place following two straight-sets wins over Pegula and Sabalenka, though the Greek's position is to be decided. The full remaining scenarios can be found below.
 Jessica Pegula (USA) vs.  Aryna Sabalenka
Head-to-head: Sabalenka leads 3-1 (Pegula leads 1-0 on hard courts, Sabalenka leads 1-0 in 2022)
1. Sabalenka has more control over her advancement prospects than Pegula. Regardless of the outcome of the first match, the coveted semifinal place will be decided by how the second match plays out. But more of the latter options fall in Sabalenka's favour. If she wins in straight sets, she will advance if Sakkari then wins one set against Jabeur. And if she drops a set, or even loses in three sets, there are still mathematical possibilities for her to go through.
By contrast, Pegula not only needs to defeat Sabalenka but for Sakkari to beat Jabeur in straight sets -- and even then, if it comes down to game percentage, Pegula could be eliminated.
2. The head-to-head is also promising for Sabalenka. At a stage when every game counts, the three-time major semifinalist will be aiming for as straightforward a win as possible. Happily for her, that's been the outcome of her last three encounters with Pegula. Sabalenka has lost just 12 games to the American in their three matches since September 2020, including a 6-1, 6-4 victory this year in Rome.
Pegula can take heart from the fact that her only win in the series was also their only previous hard-court meeting, a 6-2, 2-6, 6-3 win in the third round of the 2020 Western & Southern Open -- a career-best win by ranking at that point in her career.
3. Pegula's two losses -- plus another two in doubles -- have been tough to take. "I take back what I said about the format not really mattering," she said after losing to Jabeur after dominating the first set. "After losing four times in three days, it definitely sucks more than when you have a week to reset in between tournaments."
Pegula, who will be competing for the United States in next week's Billie Jean King Cup Finals in Glasgow, was surprised to learn that she was mathematically still alive in Fort Worth. Keeping her mind on this week's tournament will be a supreme mental test.
 Ons Jabeur (TUN) vs.  Maria Sakkari (GRE)
Head-to-head: Jabeur leads 2-1 (Sakkari leads 1-0 on hard courts, Jabeur leads 1-0 in 2022)
1. Jabeur will have clarity over exactly what she needs. Unlike Sabalenka and Pegula, who will have to wait for the second match to unfold to find out whether they're still in the tournament, Jabeur will have her fate entirely in her hands.
If Sabalenka has beaten Pegula in straight sets, Jabeur will also need to win in straight sets. If Sabalenka has beaten Pegula in three sets, Jabeur just needs a win.
If Pegula has beaten Sabalenka, Jabeur will only need to win one set to guarantee advancement.
2. Sakkari promises she won't let up. It's not unusual for players who have already sealed a semifinal place to lose their final round-robin match. Sakkari, into the last four at the WTA Finals for the second year in a row, is mindful that she doesn't want to lose her momentum. "I'm gonna be locked in as I was the last two matches, there's no question about it," she said. "Relaxed is not going to work for me."
Indeed, Sakkari feels that she will be able to swing even more freely now that there's no pressure on her, pointing out that after sealing her qualification for last year's WTA Finals, she was able to play a "lights-out" match to beat Simona Halep in the Moscow quarterfinals.
3. Their last two encounters have featured unlikely comebacks. Jabeur and Sakkari first met at ITF level, with the Tunisian winning 7-5, 6-1 in the second round of the 2015 Sobota W75. They have split two meetings at tour level, with the victor coming from behind in both.
In the 2020 Ostrava quarterfinals, Sakkari trailed 6-3, 2-0 -- before reeling off 12 of the last 14 games to win 3-6, 6-3, 6-1. In the Rome quarterfinals this year, Jabeur was 6-1, 5-2 down, before taking 11 of the next 12 games for a 1-6, 7-5, 6-1 triumph.
In doubles, the Rosie Casals Group will also conclude. The first match, in which No.6 seeds Xu Yifan and Yang Zhaoxuan take on No.8 seeds Desirae Krawczyk and Demi Schuurs, will decide second place -- and the remaining semifinal spot -- in the group. Krawczyk and Schuurs lead the head-to-head 2-0, having defeated Xu and Yang in straight sets in both Rome and Toronto this year.
No.1 seeds Barbora Krejcikova and Katerina Siniakova will then face No.3 seeds Coco Gauff and Pegula. Krejcikova and Siniakova have already advanced to the semifinals as group winners; Gauff and Pegula cannot advance. This will be their first meeting as teams.