Rafael Nadal ended the season on top of the world to give men's rankings a familiar look, but a new group of women shows that the old ranger can be overthrown.

The world's number one in Spain Novak Djokovic won their two Grand Slam titles in 2019, keeping the time of the father and young competitors alive for another year. But Ashleigh Barty and teen Bianca Andreescu were new faces on the list of the biggest women winners when familiar names disappeared from the show.

Here is a look at some great conversation topics for this season.

Can Nadal stay ahead in 2020?

Rafael Nadal reached at the Italian Open in May without a title in 2019.

He beat Novak Djokovic in the final and lost only three games for the remaining season, and won the French Open and the US Open before inspiring Spain to the glory of the Davis Cup on the homeland, where he finished as the world’s number one for the fifth time.

By the combined age of 103, Nadal, Djokovic and Roger Federer continue to dominate men's tennis and a brave player is required to predict their imminent disappearance.

But in the end, there is a sense of a reliable challenge from an exciting young crop, including Daniel Medvedev, who drove Nadal in the US Open, winner of ATP Finals Stefanos Tsitsipas.

"I think I am about to win the Grand Slam champion," Tsitsipas said after beating Dominic Thiem in the final in London.

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23-year-old Australian Ashleigh Barty rose from anonymity at number 15 in the world at the end of 2018 to top the overall standings after that by winning the French Open and WTA Finals along the way.

Teen Bianca Andreescu of Canada made the most dramatic shot, from 178th to fifth in the world, beating Serena Williams in the US Open final to become the first Canadian to win the Grand Slam singles title.

Andreescu announced during her win at Flushing Meadows "NextGen is here".

"You see a lot of new faces and I think we'll just get better from here." Federer’s Wimbledon pain

Roger Federer earned two points at Wimbledon in his special service to beat Novak Djokovic and win his 21st Grand Slam title. 

Instead, he hesitated. Djokovic, in a match that lasted less than five hours, won his sixteenth Garnd Slam and two months later Nadal won his nineteenth.

"It's an incredible opportunity," said the 38-year-old Swiss veteran, and who must fear his days as the ultimate leader on the list are numbered.

Serena’s court problem

Serena Williams runs out of chances to win the 24th title of the Grand Slam tournament that would have taken her to the Margaret Court’s record.

The 38-year-old reached the final in both Wimbledon and US Open, but he only won four games against Simona Halep in London and lost in consecutive sets to Bianca Andreescu in New York.

She followed up on the losses in the finals of both events the previous year, indicating that Williams was feeling the pressure.

Speaking after her defeat at the US Open, she reduced the search for the court’s record.

"I'm not necessarily chasing a record. I'm just trying to win the Grand Slams ," he said.

"It's definitely frustrating, but for the most part I'm still here. I'm still doing what I can do." The return of the year

In January, British former world number one Andy Murray admitted that the 2019 Australian Open could be his last tournament during a  press conference. But the 32-year-old Scottish returned to court after hip resurfacing surgery and beat veteran Stan Wawrinka in the European Open Championship final in October.

"It means a lot," Murray said after his victory. "The past few years have been very difficult ... I did not expect to be in this position, so I am very happy." A star is born

After being the youngest player to win the Wimbledon title, Coco Goff, 15, surprised Venus Williams five time champion in the first round in consecutive sets, belying her ranking 313.

"My dream was to win. That's what happened," said the American, whose career at the All England Club ended in the final by champion Simona Halep in the fourth round. Gauff reached the third round of the US Open before winning the maiden title in Linz.

At the end of 2018 she ranked 875 but will reach 2020 at 68

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