Definition: The Grand Slams are the four most prestigious tournaments in the world: the Australian Open, Roland Garros (the French Open), Wimbledon, and the US Open. Held every year, they are distinguished by participation from almost every top player and by their two-week duration, 128-player draw in men's and women's singles, and best-of-five-sets format for men. It's extremely rare for a player to win all four events, "the Grand Slam," in one calendar year.

