The tiny nation of Switzerland has, it seems, something of an unnatural proficiency for producing world class tennis players. The country with a population of just 8 million currently has the best player in the history of the game, Roger Federer, the current French Open champion, Stan Wawrinka and two women inside the world’s top 15, Timea Bacsinszky and Belinda Bencic.

Yet it is arguable that none of these four has enjoyed the best year of all the Swiss players. Rather, that accolade goes to Martina Hingis, who won five grand slam doubles titles in 2015, taking her total number of grand slam wins to 20.

Hingis has been around forever. Literally. Ok, not quite, but it feels like it. The Swiss prodigy burst onto the tennis scene in 1995 when, as a 15 year-old, she won her first grand slam title- the women’s doubles at Wimbledon alongside Helena Sukova. Just a few months later, the teenager won her first singles grand slam title at the Australian Open to become the youngest grand slam singles winner of the 20th century at 16 years and 3 months. A slew of further records was to follow; in March of 1997, Hingis became the youngest world number one in the history of the game. Then, that summer, she became the youngest Wimbledon champion since 1887. A US Open title followed with only defeat in the French Open final denying her the coveted calendar grand slam.

Hingis’ emergence was like a breath of fresh air to the sport; her sublime court craft, her tennis brain and her finesse were unlike anything that women’s tennis had ever seen. But the Swiss’ reign at the top was relatively short lived; her grand slam singles titles would, in the end, total five but a raft of injuries, including two ankle surgeries, and the arrival on the scene of more powerful players such as the Williams sisters and Jennifer Capriati made Hingis’ life more and more difficult. At the age of just 22, Hingis retired from the sport.

A comeback was staged in 2005 but it was wholly unsuccessful; Hingis did not come close to adding to her grand slam singles tally and her return to the game came to an ignominious end in 2007 when she tested positive for benzoylecgonine, a metabolite of cocaine. While the amount detected was tiny and Hingis claimed that the substance was in her system as a result of contamination rather than intentional ingestion, she was nevertheless suspended from tennis for two years.

While it was Hingis’ singles prowess for which she was hailed as one of the all-time greats, her doubles game was, arguably, even more impressive. Her anticipation, positioning and deftness of touch made her one of the greatest doubles players the game had ever seen but there was one drawback; to win at doubles you must play with someone and Hingis struggled to hold down partnerships. She completed the doubles grand slam in 1998, winning three of those titles with Jana Novotna but she unceremoniously dumped Novotna the following year, calling her “too old and too slow’. A partnership with Anna Kournikova was then struck up but even two grand slam titles were not enough to keep the pair together with a shouting match over who was “the queen”, ending the partnership.

Such a career would have been more than enough for most but not for Hingis and she made her second comeback in 2013. Initially, it appeared to have been an unwise decision but 2015 has proven Hingis’ judgement to be entirely sound. Two women’s doubles and three mixed doubles titles have been won this year and this weekend, the Swiss who is currently ranked number one in the world with Sania Mirza of India, will aim to finish her year in style with victory in the WTA Tour Finals in Singapore.

It is rare that comebacks are ever judged an unmitigated success but Hingis’ latest one cannot be seen as anything else. She looks more relaxed and carefree in this incarnation than she ever has and this renaissance shows no sign of slowing down. Her five grand slam titles in 2015 have ensured that she has earned more money than established singles players such as Caroline Wozniaki, Victoria Azarenka and Ana Ivanovic with the Swiss raking in over $1.5 million dollars this year alone.

Remarkably, Hingis has only recently turned 35, just a year older than Serena Williams and with doubles considerably less taxing on the body than singles, there seems little reason why Hingis cannot maintain this level of success for a considerable time. A return to singles has been ruled out- the game has moved on to such an extent that Hingis could not compete with the powerhouses who now dominate the women’s game- but there is unquestionably something heartening to see a player of Hingis’ calibre dominate the circuit, albeit the doubles circuit, 20 years after her debut.