The Defense Runs them Down

With runners on, the ball gets put into play. A fielder gets to the ball and tries to make a play— maybe it works out, maybe it doesn’t— and in the aftermath, the defense spots a runner who is either attempting to run to the next base, or who has strayed just a little too far off the base that they made it to on the play. The fielder then fires the ball off to another infielder, extending the play in the hopes that they can get this other runner out.

Getting that out requires a tag, because the runner is not being forced to run to the next base; they’re just being opportunistic. If the tag is applied in the middle of the base path, then there’s little drama involved, but if the tag happens as the runner is sliding into the base, then things can get a little more interesting; the runner can employ certain moves to try to avoid the tag, while even if the fielder misses that tag the first time, if they keep the tag applied and the runner either slides past the base or pops off of it just a little bit, they can be called out¹.

If the defense goes after another baserunner, they might be able to snag an easy out, possibly by first trapping a runner in something called a "rundown." But, they could just as easily throw the ball away, and if they manage to do that multiple times on the same play, the batter can advance all the way around the bases for what’s referred to as a “little league home run²,” with any additional runners also scoring. The batter gets credit for the initial play (unless that initial play was also an error), with the additional bases coming on the error(s).