The No. 1 ranking remains up for grabs at this year’s WTA Finals, but only just, with Iga Swiatek trailing Aryna Sabalenka by 1,046 points. It seems fitting in a year of returns, breakthroughs and overall competitiveness on the women’s tour in 2024.

Coming into this week, 65.8% (1,142/1,736) of matches on the WTA Tour were won by the pre-match favourite, according to Opta’s Win Probability Model. That’s a 3.6% drop on the same win rate in 2023.

From the 38 finals with a pre-match favourite, 26 went on to eventually claim tournament victory, including seven of the 10 WTA-1000 this year.

Two of three winners from the remaining WTA-1000 events ended up qualifying for the year-end tournament in Riyadh, with Jasmine Paolini and Coco Gauff’s respective victories in Dubai and Beijing. Danielle Collins (Miami) only just missed out on a berth.

Among the qualifiers for this year’s WTA Finals, Paolini has won the most matches on the WTA Tour as the underdog this year. She has seven such wins – holding a 50% win rate this year against the pre-match favourite.

Meanwhile, among players with 10+ matches as the favourite on the WTA Tour this year, Karolina Muchova’s impressive late-season return from injury saw her hold the best winning percentage at 92.9%. Her only loss as the pre-match favourite came in the Beijing final against Gauff.

Even in tournaments where the pre-match favourites seemingly had straightforward paths to the sharp end, it was not necessarily simple. While Berlin, Iasi and Linz had the highest win rates per WTA event for the pre-match favourites this year, the eventual tournament victors each had to win from match point down en route.

Jessica Pegula ultimately did so in the final on the Berlin grass, saving five match points against Anna Kalinskaya. It was one of two WTA events this year where the winner won from match point down, including Swiatek’s epic triumph over Sabalenka in Madrid where she saved three match points.

Following wins over Sabalenka in Madrid and Naomi Osaka at Roland Garros, Swiatek was one of four players to win multiple WTA Tour matches this year from match point down, along with Pegula, Mirra Andreeva and Linda Noskova.

Since the start of the 2023 season, Swiatek is the only player to win multiple matches at grand slams from match point down, after also saving two en route to victory over Belinda Bencic at Wimbledon last year. The current WTA No. 2 was just as capable leading from the front this year, winning 88.2% of her matches as the pre-match favourite according to Opta’s Win Probability Model, while she is 53-2 at WTA level after winning the first set this year.

Sabalenka wasn’t too far behind Swiatek, winning 81.0% of matches when she came in as the pre-match favourite. Sabalenka’s 34 such wins are also the most of any player so far on the WTA Tour this year.

However, the current WTA No. 1 has lost the most matches in 2024 of any player who held a 80+% pre-match win probability, including a defeat in Dubai to eventual Olympic finalist Donna Vekic, where her win probability jumped to 93.4% after taking the first set.

Something to keep in mind for next week’s year-end event, though, is that it remains Sabalenka’s only loss this year on hard court after winning the first set. Meanwhile, she’s won her last 23 matches on the surface after winning the first set.

The biggest single-match upset of the year is reserved for Shuai Zhang, who defeated Emma Navarro in Beijing despite only sitting at 8.7% as the pre-match underdog. That came after snapping a 24-match losing streak in the previous round against McCartney Kessler. In her win over Navarro, Zhang became only the third player ranked outside the WTA’s top 500 to claim a top 10 win at a WTA-1000 event, since the format’s inception in 2009.

Both building late-season form, Magda Linette and Rebecca Sramkova claimed the most WTA Tour victories in 2024 coming in as the pre-match underdog, with 13 wins each.

With eyes forward to the upcoming WTA Finals, it appears to be one of the more open fields in recent years, with a number holding a legitimate claim to taking out the year-end event.

Opta’s Live Win Probability Model enables us to determine the key moments where tournaments and matches are won or lost, predicting the likelihood of either player winning a set or match in any given scenario.