Coco Gauff rallies to win, puts the pressure on Jessica Pegula at WTA Finals

Thursday's WTA Finals singles action was focused on American players Coco Gauff and Jessica Pegula as they both battled to advance to the semifinals. Linda Noskova had already clinched her spot in the semifinals from this group, but would it be Gauff or Pegula joining her?Gauff made an early statement in the day, and if you ever doubted her competitiveness, Thursday proved once again you never should. Gauff won the first set Thursday against Marta Kostyuk 6-4, but then fell behind in the second and started to feel some back discomfort in her back, calling a trainer to come and take a look at it. After some stretching and wincing she went back out there but soon fell behind 5-1. Ailing and struggling to find her form, the announcer suggested she should consider dropping one more game and get ready for the third set. That's not how Coco rolls. Remarkably, she fought and clawed her way through the injury, started playing lights out tennis and remarkable won six straight games for a gutsy 6-4, 7-5 win. Now she'll have to wait to see if it was all worth it. Gauff's win forces Pegula to have to win against Noskova later in the day. If Pegula wins, she advances and Gauff is eliminated due to tiebreaker rules. If Pegula loses, Gauff moves into Saturday's semifinals. The stage is now set, but no matter how the rest of the day goes, Gauff showed once again, what a great competitor she is.Thursday's singles WTA Finals singles schedule and order of playNoon: Marta Kostyuk (0-2) vs. Coco Gauff (1-1)Following: Linda Noskova (2-0) vs. Jessica Pegula (1-1)Coco Gauff and Jessica Pegula scenarios and tiebreakers explainedBoth players are 1-1 through two matches with Gauff having beaten Pegula in three sets in a head-to-head match. Gauff plays Kostyuk on Thursday and Pegula plays Noskova.For Gauff to advance: It's pretty simple, she needs to win AND have Pegula lose, that's the only way due to some somewhat intricate tiebreakers that did not fall in Gauff's favor.For Pegula to advance: She simply needs to win OR lose and have Gauff also lose. She wins all possible tiebreakers over Gauff if they all end up in a three-way tie at 2-1 with Noskova, or a three-way tie at 1-2 with Kostyuk.Here's why Pegula has the edge over Gauff in the tiebreakersThe first tie-breaker in a three-way tie is the player with the best "set percentage" meaning who has won the highest percentage of the sets they played. Entering Thursday play, Gauff has a set record of 2-3 and Pegula has a set record of 3-2, a lot of that comes down to the set Pegula won off of Gauff in their head-to-head match.Let's say on Thursday Gauff beat Kostyuk in straight sets and Pegula beats Noskova in straight sets. That would put Noskova, Gauff and Pegula in a three-way tie at 2-1, with the top two advancing. Noskova will have a "set record" of 4-2, Pegula would have a set record of 5-2 and Gauff would have a set record of 4-3. You can see that Gauff would have the lowest percentage of sets won among the three. Even if Pegula beat Noskova in three sets, that would put both Noskova and Pegula at 5-3 and Gauff at 4-3.In the scenario where they both lose on Thursday, Noskova would be 3-0 and obviously claim the top spot and there would be a three-way tie between Pegula, Gauff and Kostyuk for one spot. If Gauff lost in three sets and Pegula lost in straight sets, that would put Gauff at 3-5 and Pegula at 3-4 and Kostyuk at 2-4 so Pegula would still have the edge.This article originally appeared on Palm Springs Desert Sun: Coco Gauff rallies to win, puts the pressure on Jessica Pegula at WTA Finals