If Novak Djokovic is going to beat many records in tennis and will be for some years the best player in the world, the greatest rivalry of tennis in the 21st century does not concern him. Yes, it is the matches between him and Rafael Nadal that have taken place most often in men's tennis, but the greatest rival of the Spaniard Nadal is the Swiss Roger Federer, whom he has faced nine times in the final of Grand Slam, as much as the Serbian. Both have dazzled the tennis world since the beginning of the 2000s, while Djokovic revealed himself a little later and really asserted himself at the highest level from 2011.