Grand Slam

What is a Grand Slam?

A grand slam is a home run hit with the bases loaded. That means there are runners on first, second, and third base when the batter goes deep. It results in four runs scored, the maximum possible on a single play.

Grand slams are among the most impactful moments in a game. Not only does the batter score, but all three base runners do as well. It’s one of the biggest momentum-shifting swings in baseball and often changes the outcome of a game in one swing.

How is a Grand Slam used?

A grand slam is used to measure high-leverage power hitting. It shows a player’s ability to deliver when the bases are loaded and pressure is high. While hitting with the bases loaded is rare on its own, going deep in that opportunity is even rarer — which becomes valuable to any team. Historically, grand slams are a big part of signature games and highlight moments for power hitters.

How to calculate a Grand Slam?

There’s no formula to calculate a grand slam — it’s a result of the situation. It occurs when:

The batter hits a home run
The bases are loaded at the time of the swing

All four runs count as earned runs against the pitcher, and the hitter is credited with one home run and four RBIs. Grand slams count the same in the box score as any other home run, but their impact is amplified in certain game situations, thanks to win probability added.