Rafael Nadal & Dominic Thiem among the hits of 2020, Tsitsipas & Berrettini among the 'flops': Paolo Bertolucci

Former World No. 12 Paolo Bertolucci believes Rafael Nadal, Dominic Thiem, Daniil Medvedev and Jannik Sinner were the best performers in 2020. He also branded Stefanos Tsitsipas and Matteo Berrettini as the most prominent 'flops' of the year.

Rafael Nadal won a record-extending 13th French Open title in Paris this season. That also marked his 20th Major overall - tying Roger Federer for the most Grand Slam singles titles in men's tennis history.

Austria's Dominic Thiem meanwhile won his first Slam, at the 2020 US Open. He also reached the finals of the Australian Open and the ATP Finals, falling short to Novak Djokovic and Daniil Medvedev respectively.

Medvedev incidentally won the Paris Masters right before triumphing at the season-ending championships, to end his season on a terrific note.

The 19-year-old Jannik Sinner also had a great run in 2020. He won the first ATP singles title of his career at the Sofia Open, and reached his first Grand Slam quarterfinal at the French Open (where he lost to Rafael Nadal).

Paolo Bertolucci made note of all these players in a recent interview, where he was asked to pick his tops and flops of 2020.

"In the tops, I put Daniil Medvedev, Jannik Sinner, Rafael Nadal and Dominic Thiem, in the flops Matteo Berrettini and Stefanos Tsitsipas," Bertolucci said.

The 69-year-old Italian also believes Rafael Nadal will continue to dominate the clay court tournaments, including Roland Garros, as long as he remains healthy.

Dominic Thiem's matches against Rafael Nadal, Novak Djokovic & Daniil Medvedev at the ATP Finals were incredible: Paolo Bertolucci

Dominic Thiem and Rafael Nadal at the Nitto ATP Finals

Paolo Bertolucci, who won the Davis Cup with Italy in 1976, claimed that this year's ATP Finals in London had some incredible matches - particularly those involving Dominic Thiem.

"Many, even if the more recent ones remain more in mind," Bertolucci replied when asked about his best matches of the season. "At the Masters, I would say that there were 3-4, the final had an excellent level, but also the Nadal-Thiem match and the first semifinal, the one between the Austrian and Djokovic. At the ATP Finals, I am convinced that there have been super matches, a frighteningly high average."

Bertolucci also had high praise for his countryman Jannik Sinner, who he believes needs to focus on a few things to step up to the next level.

"Jannik Sinner has to work from a technical, tactical and physical aspect. If he is good at increasing his speed, even better. I hope he will be able to play a lot of matches to gain experience and that he will go up a few steps in the rankings," Bertolucci added.