Who is the next women's star? As of now, it's anybody's guess

Whither women’s tennis? Serena Williams wins – when she plays. When will that be? We don’t know. Maria Sharapova will play on April 26th in Stuttgart but she hasn’t played for 15 months. How will she play? We don’t know.

When will Victoria Azarenka start combining motherhood with a return to the tour? Not sure. When will the remarkable Venus Williams find it impossible to go on winning matches at the age of 36, or 37, or 38? Only she knows – and maybe even she isn’t sure.

When will Petra Kvitova recover from the horrendous knife attack that damaged her hand? Happily the two-time Wimbledon champion seems to be progressing. But a date for her return? Don’t know.

I don’t think I can remember when the women’s game has faced so many imponderables. I suppose the men’s game has spoiled us for certainties over the past decade. If one of the Top 4 doesn't win, one of the others will. The winning statistics Roger Federer, Rafa Nadal, Novak Djokovic and Andy Murray have racked up at Grand Slams and the ATP 1000 level are staggering. It is inconceivable that another quartet will dominate the game so thoroughly for so long ever again.

The women’s game has too many variables for it to produce anything similar, although, for a period in the early 2000s, the remarkable Williams sisters made a good attempt at turning the WTA tour into a family affair. And that dominance might have been extended further had it not been for a variety of health problems, not solely related to physical injuries.

The extraordinary factor has been the inability of strong, talented players to maintain a serious challenge to Serena. Ana Ivanovic won the French Open in 2008, reached No 1 in the world, became overwhelmed by the pressure and fell away. Dinara Safina was No 1 in 2009 but, without a Grand Slam title, could not maintain it. Lack of a Slam title also made life strangely difficult for the determined Caroline Wozniacki in 2010 and 2011, but she doggedly held on to her No 1 ranking for 67 weeks.

Then there were the shooting stars – Sam Stosur upsetting Serena to win the U.S. Open in 2011; Marion Bartoli stunning Wimbledon by beating Sabine Lisicki in the unforeseen 2013 final.

But nothing was less anticipated than the all Italian affair at the U.S. Open in 2015, when Flavia Pennetta beat her childhood friend Roberta Vinci in the final.

Li Na created much humor and happiness with her wins at Roland Garros in 2011 and Melbourne three years later, but then she decided it was time for a family.

So we waited yet again for a real challenger to Serena. Garbine Muguruza looked as if she might be ready to fill the bill when she played so beautifully to win the French Open last year. But once again, the spotlight seemed to intimidate the elegant Spaniard and she has not built on that triumph.

Angelique Kerber won two Slams last year and deservedly finished No 1. But Dominika Cibulkova beat the German in the final of the WTA Finals at Singapore and Kerber has not played like a No. 1 so far in 2017.

In fact it felt as if we were experiencing all our yesterdays when Serena ended up playing, and beating, Venus in the final of the Australian Open in January. Venus had not been in the final of a Slam since Wimbledon 2009, but she has been showing a lot of younger players how to get through the tough business of winning tennis matches this year and, now ranked No 12, she is not done yet.

Former Wimbledon doubles champion Peter McNamara, who is back on the tour coaching talented Chinese player Qiang Wang, says the explanation is simple. “Serena and Venus, along with Sharapova, just generate more power,” says the Australian. “They hit the ball harder and most women players can’t deal with it.”

McNamara also thinks almost all the women players in the Top 80 can beat each other on any given day. “They play the same style,” he says. “So few have anything different to offer. Virtually none of them can volley. I know of players who were prevented from playing doubles and told not to learn the volley. So how can you get any variety?”

It is no use searching for a thread that points in any particular direction this year. Serena has won the Slam; Elina Svitolina of the Ukraine has won the most matches on tour; Karolina Pliskova has risen to No. 3 in the world off the back of title wins in Brisbane and Doha, but could not get past the quarterfinals at the Australian Open or the semifinal at Indian Wells last week, where she lost to the rejuvenated Russian veteran, Svetlana Kuznetsova. However, Pliskova, whose twin Krystina finished last year ranked No. 61 on the WTA Tour, seems the most likely to break through and win big in the coming months.

But we don’t know. One could pick a dozen possible winners here at the Miami Open and still miss out on the eventual champion. Elena Vesnina played the best tennis of her 12-year-old career while winning Indian Wells, another unexpected triumph for a hard-working player.

American fans will be hoping that Madison Keys, who has the ability to hit the ball as hard as anyone, can continue her comeback after injury with a strong performance in Simona Halep’s quarter of the draw. But Keys may have to face Britain’s Johanna Konta in the fourth round, and Konta proved during her rise to the Top 10 last year that she is a danger to anyone.

But what of Halep, the aggressive Romanian who was No. 2 in the world in 2015? Halep won titles in Madrid, Bucharest and Montreal last year but has struggled to make an impact over the past three months. Her loss to Shelby Rogers in the first round in Melbourne probably had something to do with the knee injury that forced her to withdraw midway through the St. Petersburg tournament two weeks later. With Darren Cahill, one of the best coaches in the business at her side, Halep could be the player to start providing the consistent performances that seem beyond her contemporaries.

But hold the predictions. At the moment, as far as women’s tennis is concerned, we just don’t know.

Originally published on TennisChannel.com. Read more articles by Richard Evans here.

Starting Tuesday, March 21st, watch Tennis Channel Plus for the biggest WTA matches of the day from the Miami Open!​

Tennis Channel Plus will have 12 straight days of WTA Action, including the Quarters, Semis and Final.

All of the best action — Live and On Demand — on any screen — anywhere — only on Tennis Channel Plus!

Tennis Channel Plus is THE ultimate destination for WTA action in March. Subscribe today at BuyTCPlus.com.