During the course of his illustrious 22-year professional career, Roger Federer has met many an opponent - 344 of them to be precise. 233 different players have never managed to beat Federer, with matches against this group (582) accounting for almost 50% of the Swiss maestro's career win tally of 1237.
Of the remainder, only 26 players, seven of whom are active, have a winning head-to-head record against the record 20-time Grand Slam champion. Evgeniy Donskoy (2017 Dubai 3R), Thanasi Kokkinakis (2018 Miami 2R) and Andrey Rublev (2019 Cincinnati 3R) are the only active players, with one win apiece, never to have lost to Federer.
You may also like: Federer's 5 most prolific rivalries of the 2010s
In Grand Slam tournaments, where Federer (357) has the most wins of any player in the Open Era, Novak Djokovic and Rafael Nadal (10 apiece) lead a small group of 8 players to have beaten the Swiss maestro on multiple occasions. 26 other players have beaten Federer only once in Grand Slams, the last two being Stefanos Tsitsipas (2019 Australian Open 4th Round) and Grigor Dimitrov (2019 US Open Quarterfinals).
Djokovic is the only player to beat Federer at all the four Grand Slam tournaments, completing the set with a victory over the Swiss maestro in the 2014 Wimbledon final.
On that note, let us have a look at 5 players whom Federer has faced in the highest number of different tournaments.
#5 Stan Wawrinka - 16 tournaments
Federer has met his good friend and compatriot Stan Wawrinka in 26 matches across 16 different tournaments, overwhelmingly dominating their head-to-head rivalry 23-3. All 3 of Wawrinka's wins over his illustrious compatriot have come on clay - 2009 Monte Carlo Round of 16, 2014 Monte Carlo final and 2015 Roland Garros quarterfinal.
Excluding the Olympics, Federer has faced Wawrinka in all 5 tournament categories - Grand Slams, ATP Finals, Masters 1000, ATP 500 and ATP 250.
One of 8 opponents he has faced at all 4 Grand Slam tournaments, Federer has also played Wawrinka at the season-ending ATP Finals, Masters 1000 (7 tournaments), ATP 500 (Basel, Dubai, Rotterdam) and ATP 250 (Stockholm).
The most meetings (4) between the pair have occurred at the French Open (Federer leads 3-1) and Indian Wells (Federer leads 4-0). Monte Carlo is the only tournament where Federer has failed to beat Wawrinka, going 0/2 against the three-time Grand Slam titlist.
You may also like: 3 milestones awaiting Federer in 2020
#4 Richard Gasquet - 16 tournaments
Federer has met his fellow single-hander Richard Gasquet in 20 matches across 16 different tournaments. The Swiss leads the head-to-head against the Frenchman 18-2, and both of his losses have come on clay - 2005 Monte Carlo Quarterfinals and 2011 Rome Round of 16.
The Swiss maestro has faced off with Gasquet in all Grand Slam tournaments except Roland Garros, and also the ATP Finals, 8 different Masters 1000 tournaments (all except Miami), ATP 500 (Halle and Dubai) and the Davis Cup (2014 final). Federer has won all of their last 10 meetings since losing in 2011 Rome.
Dubai, Madrid, Paris-Bercy and Wimbledon (2 apiece) are the tournaments where Federer and Gasquet have played most often.
Also Checkout: Tennis 2020 Schedule
#3 Novak Djokovic - 16 tournaments
With 49 meetings spanning across 16 tournaments and 13 years, no player has played Federer as many times as Novak Djokovic has. No player has also beaten Federer as many times (26) as Djokovic has, the most recent one being the pair's epic 2019 Wimbledon final where the Serb became the first winner at the grasscourt Major in 71 years to have saved multiple championship points.
Djokovic has also denied Federer on two other occasions from match points down - both such instances happening in the US Open semifinals (2010-11).
You may also like: 8 tournaments where Federer has had the most missed opportunities
One of only 8 players to face Federer at all four Grand Slam tournaments, Djokovic is the only one of the octet to beat the 20-time Major winner at the all four. Djokovic and Nadal with 10 wins apiece form the only pair to have beaten Federer multiple times in Grand Slam matches.
Djokovic and Federer have also clashed 6 times at the ATP Finals, with each player winning thrice apiece; that is the highest number of times they have met at any tournament. Federer and Djokovic have also met at all Masters 1000 tournaments except Madrid, and twice in ATP 500 tournaments (Basel and Dubai).
With 14 wins (also Nadal), no player has beaten Federer in as many tournament finals as Djokovic has - a tally which includes 4 Grand Slam finals.
#2 Lleyton Hewitt - 16 tournaments
Lleyton Hewitt is the fourth player Federer has faced off against in exactly 16 different tournaments, with the Swiss player leading the pair's head-to-head 18-9.
Federer and Hewitt have clashed at 3 of the 4 Grand Slam tournaments (never met at Roland Garros), the ATP Finals, 6 different Masters 1000 tournaments (Hamburg was a Masters 1000 tournament in 2004), Davis Cup and 5 other tournaments.
Federer went 3/5 in tournament finals against the two-time Grand Slam champion, with his two losses (2010 Halle and 2014 Brisbane) coming in the pair's last three meetings overall.
Hewitt is the only player win each of his first three meetings with Federer, and he led the Swiss 7-2 following a Davis Cup win from two sets down in 2003 before Federer turned the tables around.
#1 Tomas Berdych - 17 tournaments
With 17 different tournaments witnessing the Roger Federer vs Tomas Berdych rivalry, it is also the highest number of tournaments in which Federer has faced any opponent. Federer leads the pair's head-to-head 20-6.
The 26 meetings between the pair have materialized in Grand Slams, ATP Finals, Masters 1000, ATP 500, ATP 250, Davis Cup as well as the Olympics. Berdych is the only player to play Federer twice at the Olympics, one of 8 players to face the Swiss maestro at all 4 Grand Slam tournaments, as well as one of 8 players to beat Federer multiple times at a Major.
Berdych became the first player to beat Federer in 24 night matches on Arthur Ashe when the Czech beat the then 17-time Major winner in 4 sets at the 2012 US Open quarterfinals. However, since a 2013 Dubai semifinal defeat, Federer has emerged triumphant on all 9 occasions he has crossed swords with Berdych.