WIMBLEDON, England — No one has any idea which of the four semifinalists will win the women’s singles title at Wimbledon on Saturday. But there is one prediction you can make with confidence: The remaining matches will be close, hard-fought contests that could easily last three sets.Women’s tennis matches keep getting longer and more grueling. Since the 2014 Australian Open, the four Grand Slams — including this year’s Wimbledon, which is not yet complete — have averaged 40.9 three-set women’s matches per tournament. That’s up from an average of 36.8 between 1988 and 2013. Last month’s French Open saw 46 women’s matches go the distance, which was the most ever at Roland Garros and tied for the fourth-highest tally at any Slam since 1988, according to the WTA. So far this Wimbledon, there have been 43 three-setters, with three matches left to play. One more would put this year’s competition in a three-way tie for the most three-set matches at Wimbledon since 1988 — the 2011 and 2008 tournaments each saw 44. Tennis’s current crop of women are, as a group, extremely talented but frequently flawed players, which means anyone can win almost any match. This is especially true while Serena Williams, the sport’s most dominant player, is off the circuit during her pregnancy. For evidence that anyone can win, look no further than last month’s French Open, where an unseeded 20-year-old — Jelena Ostapenko, who at the time was ranked 47th in the world — took home the trophy. Five of her seven matches there lasted three sets, including the semifinal and final. In the final, Ostapenko trailed by a set and 3-0 before charging to victory.Agnieszka Radwanska, seeded 9th at Wimbledon, saved two match points in the second round and beat Christina McHale, an unseeded American, in three sets. She needed three sets in the next round too, against Timea Bacsinszky, seeded 19th. Radwanska, who became a professional in 2005, said that today’s tennis is far more tense than it was in the past.“A couple of years ago, those first two rounds when you didn’t play against seeded players, it was easy,” Radwanska said. “You don’t have to play 100 percent and you’re gonna win. Obviously it’s not gonna happen anymore in tennis right now. You can play … those players that you really don’t want to play in the first round, and that’s why I think we can also see a lot of upsets in early rounds.”In men’s tennis, the late rounds of many tournaments remain compelling — it’s hard to be bored when greats like Roger Federer, Rafael Nadal, Novak Djokovic, Andy Murray and Stan Wawrinka are duking it out — but in early rounds, the excitement has fizzled. The men’s side rarely sees any early upsets, and players are more likely to retire in the middle of matches; nine men bowed out during the first three rounds at Wimbledon this year, compared to only two women. We don’t yet know if the women will have any 30-something superstars in the final this year, but the women’s matches are competitive and entertaining from the first round to the last. CoCo Vandeweghe, an American currently ranked 25th, described the men’s field as “top-heavy” compared to the women’s side.“In the women’s game, as you’ll see, there is more upsets along the way with the seeded players, because I think there is more depth in the 20s to 30s to 40s,” she said. “I think there is some very solid depth of players that can make an impact against a top player. I mean, I’m an example of that myself.”British star Johanna Konta says that anything can happen and happen quickly. She has won three three-set matches so far, including one that required 18 games in the third set. She said she worries about everyone she faces.“I don’t underestimate any opponents,” she said. “I respect each and every opponent that I’m playing because I’m fully aware of the challenges that they will bring.”Of course, no one will underestimate Konta’s next opponent. She plays five-time Wimbledon champion Venus Williams in the semifinals on Thursday.