Explained in plain English

What is a Grand Slam?

In tennis, a Grand Slam refers to the four most prestigious annual tournaments: the Australian Open, French Open, Wimbledon, and the US Open. Winning all four in a calendar year is incredibly rare, a true mark of tennis greatness. Djokovic's early exit from the US Open is significant because it's so unusual for a player of his calibre in one of these major events.