After four-and-a-half months of competition in the 2018 season, Roger Federer is the tennis player with the best win/loss record.
The Swiss won 17 matches out of 19 played, with a success rate of 89%. After Federer there is Rafael Nadal with 88%. The Spaniard got 16 wins and two losses, he lost just to Dominic Thiem in Madrid and Marin Cilic when he retired at the Australian Open.
Juan Martín del Potro fills the last place of the podium with an 81% record, with 22 wins and five losses. After them, the German Alexander Zverev with 79% (23-6), the Australian Nick Kyrgios with 76.9% (10-3), the Austrian Dominic Thiem with 76.7% (23-7) and the South African Kevin Anderson with 74% (20-7).