After Rafael Nadal won his 12th French Open title on Sunday, tennis fans can look forward to Wimbledon in three weeks time. All Nadal's dominance at Roland Garros underlines however, is the challenges facing the Men's Singles game over the coming years. A day before Nadal's triumph, the Australian Asheligh Barty was on her way to winning her first ever Women's Singles Grand Slam title. More than that, she was doing so in her first appearances past the Quarter-finals stage at any Grand Slam tournament. She may not have realised it at the time, but in doing so she continued a growing precedent in women's tennis. Over the last 10 Grand Slams, there have been nine different winners of the Women's Singles competitions. Even more staggering is that Barty's victory means that eight of these women were first-time winners. Women's tennis is competitive, unpredictable and growing fast. By contrast, the Men's Singles have all been won by three men: Roger Federer, Rafael Nadal and Novak Djokovic. A group that were once classed as the 'big four', have remained untouchable as a three in Andy Murray's absence. As fans, we have been spoilt by one or all of these players' excellence for almost two decades now. Their level of dominance is unprecedented, but it could all spell trouble for the sport in the coming years. With Murray already retiring (sort of) due to injury, Federer on the cusp of turning 38, and Nadal and Djokovic both 33 and 32 respectively, the age of the big four is coming to a close. Where have the challengers been? Source: Tennis World USA It seems strange to say that the era will soon be ending, because in reality this is something commentators have been saying for years already. Yet, in 2019 we still have a WTA top three ranking of a 32, 33 and 37-year-old. To put it into perspective, between 2003 and 2017, 52 of the 57 major titles were won by five players: the 'big four' and one other. With Stan Wawrinka winning three Grand Slams; the same as Andy Murray, he is the only player who has come anywhere close to the level of these fierce competitors. Remembering Wawrinka's occasional Grand Slam win (the last coming in 2015) it is easy to become complacent and still view him as a young upstart biting at the heels of the big four. Yet at 34, the big Swiss is also coming into the twilight of his career. Not for want of trying, but any chance to fully assert himself on the Grand Slam stage feels long gone. He's not the only one either. Juan Martin Del Potro is turning 31; Kei Nishikori will be 30 in December; even Marin Cilic, who so often earlier in his career threatened to break into the big time will be turning 31 this year. Hope for the future? The man to break the cyle?Source: FOX Sports Asia Perhaps it is a case that as the big three show, like a fine wine, male players are just getting better with age? The prevalence of powerful baseline rallies in the men's game would certainly suit this theory, but there are glimpses of the future coming through. Take Dominic Thiem for example, at 25 he is now entering his peak and secured a well earned place in the final at Roland-Garros by beating Novak Djokovic. Yes, he wasn't able to win the trophy, but coming up against Rafa on clay feels like a bit of a free pass for even the greatest players. His five-set victory over Djokovic though felt like a real coming of age performance for the Austrian and one he will look to build on at Wimbledon. With the emergence of both Stefanos Tsitsipas and Alexander Zverev over the last year, there have been other positive noises for the future. With both players making the Semi- and Quarter-finals at the Australian open this year while still in their early 20s, a particular highlight. Yet in Paris, they followed this up with a joint exit at the last 16 stage. Tennis fans should be watching Wimbledon and Queens very closely indeed, but this cannot be left to be another false dawn. Anisimova is a rising starSource: Charlies Platiau/Reuters Whatever happens over the next few years, men's tennis still has a long way to come to match the exciting developments in the women's game. Realistically only Tsitsipas and Zverev have any chance of shaking things up in the near future, but there is a whole host of talent coming through on the women's courts. The aforementioned Barty is now at the head of this list, but the French Open unearthed 17-year-old American Amanda Anisimova. Beating reigning champion Simon Halep on her way to the last four, she will now make her first appearance at Wimbledon this summer. Could she repeat Boris Becker's infamous win at the same age back in 1985? With the unpredictability of women's tennis, you could certainly bet on worse.