Who improved Roger Federer the most between Stefan Edberg and Ivan Ljubicic? The two coaches have overseen the last seven years of the Swiss career (not at the same time), between great successes and some disappointments, technical and tactical improvements and some periods marked by injuries.
After having Paul Annacone (Pete Sampras' former coach) from 2010 to October 2013, Federer decided to change something in his team, especially to improve his game on fast surfaces. The choice fell on the former Slam-winner Stefan Edberg.
From 2014 until the end of 2015 Edberg led Federer towards a second youth, improving the Swiss in the net-game and, in general, in the attack-game (in the summer of 2015 Federer showed the SABR for the first time). After a bad 2013, Federer played three Slam finals in two years (two at Wimbledon and one at the US Open, losing them against Novak Djokovic), he won the 2014 Davis Cup final and a total of 11 titles in two seasons (2014-2015).
From 2016, after the end of the partnership with Edberg, Federer hired Ivan Ljubicic (Milos Raonic's former coach) as super-coach. He was convinced thanks to the remarkable improvements of Raonic together Ljubicic. The first year was not very lucky (2016 was the worst season of Roger's career).
But the fruits of the collaboration were evident from 2017. Ljubicic also improved the defensive phase and the backhand of the Swiss, also working from the mental point of view. The victory at the 2017 Australian Open against Rafael Nadal was the beginning of a great new story.
In the 2017-2018 two-year period Federer won twice in Melbourne and the historical edition of Wimbledon 2017, for a total of 11 titles in two seasons. To this must also be added the unforgettable Wimbledon 2019 final, lost against Djokovic and, a total of 15 titles in three years.
The cumulative work of Edberg and Ljubicic allowed the Swiss Maestro to play other years, improving technically, tactically and physically. Perhaps it is impossible to say which of the two improved Roger Federer the most: without the work of one, the work of the other and the successes achieved in the last three years would not have been possible.