Grand Slam

In baseball, a grand slam is a home run when all three bases are occupied, resulting in four runs (three baserunners and the batter). It is the highest number of runs a team can score during one at-bat.

Grand slams are uncommon since the bases have to be loaded (occupied), and the batter has to hit a home run (challenging to do, especially when a pitcher doesn't want to give them anything good to hit). Additionally, if the hitter has a high batting average when the bases are loaded, the pitcher may intentionally walk them to let in one run instead of 4.

To look at the stats, the number of grand slams in the MLB each year is usually in the low- to mid-100s, and the number of at-bats in the MLB each year is generally in the 160,000 range. So that makes for a tiny chance of a grand slam.

In tennis, a grand slam is when a player wins the four major tennis tournaments, Wimbledon, US Open, Australian Open, and French Open, in a single calendar year. Some people may also use the term for when a player wins all four tournaments in their career ("career grand slam") instead of limiting it to one year.

It's incredibly challenging to achieve a grand slam in one calendar year because you must not only play at the top of your game on different court surfaces but also stay healthy during a months-long stretch of grueling play. For example, the Australian Open takes place in January, the French Open in May and June, Wimbledon in June and July, and the US Open in August and September.

Notable male grand slam winners include Rafael Nadal, Novak Djokovic, Don Budge, Roy Emerson, Andre Agassi, Ken Rosewall, and Roger Federer. And notable female grand slam winners include Serena Williams, Margaret Court, Steffi Graf, Chris Evert, and Martina Navratilova.