Roger Federer's former coach Paul Annacone has revealed the traits that make the Swiss ace one of the greatest players to ever rule the tennis court. The 19-time Grand Slam winner has surpassed everyone in terms of achievements and will be looking to further add to his tally in 2018.

Annacone coached Pete Sampras and Tim Henman at various points in their careers and was Federer's mentor between 2010 and 2014. The Swiss ace surpassed Sampras' tally of 14 majors back in 2009 and emerged from a barren spell to extend his tally to 19 in 2017.

The Swiss ace skipped the entire clay court swing of the season this year following a blistering start to the season that saw him win three of the four events he entered. He won the Australian Open and Wimbledon in 2017, his best return in a year since 2012.

Annacone revealed that all three players had an amazing understanding of their own skill set which helped them rise through the ranks. However, he warned any upcoming star that talent alone does not take you anywhere and that you have to understand your strengths in order to be successful.

"All three of those guys had an amazing understanding of their own skill set," Annacone told Express Sport. "An understanding of what they do incredibly well. Sure, their talents are off the charts, so that's one thing. But the second thing was they understood their strengths on the tennis court.

"They know what they're best at and they give themselves continued opportunities in the most pressure-filled situations to win or lose doing what they do well. Then if they lose, they're very pragmatic about it, because they try to use their biggest strengths in the biggest moments.

"And either on that day they didn't get over the line, or the other guy was too good. So they can absorb the pain of the loss and then go back to the drawing board, go 'OK, this is what happened'," Annacone added.

"There's a very strategic, meticulous process that they go through. They do love the victories and the pain of the defeats do sting. But not so much that they are drowning in either of those emotions."

Roger Federer
Roger Federer won seven titles in 2017, including two Grand Slams Getty