For the first time in nearly a decade, I’m starting the baseball season with optimism. I’m sure the Mets will find some way to make me regret that, but for now, here’s a distinction most baseball fans ignore:

When a batter hits a ball into fair territory, and the ball leaves the playing area, but does not do so on the fly (and at least 250 feet from home plate), the batter is awarded a double. See MLB Rule 6.09(e)-(h). The typical example of this is a ball bouncing over the outfield fence. Most fans would call this a “ground-rule double.” But it’s not. It’s an “automatic double.” A “ground-rule double” is one that is awarded based on the idiosyncratic rules of particular ballparks. Another summary is here.