For more examples, click here.

A Double into the Outfield

A batter advancing to second base on a base hit, no matter where the ball is hit, and provided there's no error on the play, is called a "double". There are some other considerations here, and we'll get to them in a second.

For a ground ball to wind up as a double, the ball has to go through the infield at the exact right spot— usually we're talking down the first-base or third-base lines. Or, the defense has to be lackadaisical to the point of being in a coma¹.

And speaking of the defense— you'll sometimes see a hitter hit a fairly innocuous-looking single, but then they notice the defense sleeping a bit, and they keep on trucking into second. This type of play is usually called a "hustle double," and when it works, it’s fantastic for the offense. Less so for the defense, obviously. If it doesn't work (that is, if the runner gets tagged out at second), then the embarrassment can swing the other way, obviously. If the batter/runner makes it to second, they get a double out of it; if they don’t, they’re still credited with a single.

Just because a batter hits the ball and winds up on second, does not mean they are always credited with a double, as we hinted at the start of this section. An error is an obvious example— either the error allows the batter to reach base when they wouldn't have, or to advance a base instead of staying at first. Either way, no double. Similarly, if a batter reaches first when there are other runners on base, and while the defense is preoccupied with those runners, the runner on first moves up to second, that doesn't count on a double. That's a single, with the advance coming on the defensive play. Usually this means the runner is going to second while the fielders are throwing the ball, so it's called an advance on the throw. The distinction between “double” and “single + advanced on throw” usually becomes one of those “you know it when you see it” type of things; if the batter was going to end up at second no matter what the defense did, it’s a double. Otherwise, it’s a single with options.

Ultimately, if there are runners on, and the batter hits a double, odds are really, really good that those runners are going to score. There are exceptions, of course: a runner who started on first might only make their way to third, for example. Or, maybe that runner goes for broke and tries to score anyway. Either of these scenarios give the defense a chance to get an out somewhere; otherwise, the play ends, and the inning continues.