Novak Djokovic has just become the first male tennis player since Rod Laver in 1969 to hold all four Grand Slam titles at once. His latest French Open victory means that Djokovic is arguably the most dominant athlete on the planet right now, with the possible exception of Usain Bolt. This Serb has put together the most amazing record of wins in tennis, and now has a shot at overtaking Roger Federer as the greatest tennis player of all time. At the French Open, once the initial hiccoughs were overcome, he took World Number Two Andy Murray apart with clinical efficiency, but also with some unbelievable shots—combining elegance and guile. It is definitely time to ask just how high Djokovic’s ceiling is, or if one even exists. What is almost certain as we head into Wimbledon is that the defending champion seems well on his way to becoming the best tennis player ever.