Click here for more examples (though note that these are only plays at home where the runner is out; for runners being safe in this situation, please see the Inside the Park Home Run):

A Play at the Plate

It’s one of the most exciting plays in baseball: a runner rounds third and steams towards home, while the defenders relay the ball towards the catcher. Will the ball get there first, or the runner?

Okay, let’s back up a second— plays at the plate are much like plays on any other base: when there’s a force play on, all the defense has to do is get the ball to the catcher before the runner touches home plate. If they do, the runner is out, otherwise it’s a run. If it’s not a force, then the defense has to tag the runner before they touch home plate. The tagging fielder has to retain the ball through the process of the tag; if they drop the ball, or it gets knocked loose somehow¹, the tag won’t count. Unlike the other bases, the runner doesn’t have to stop on home plate; they can slide past home, and as long as they’ve actually touched, they’re safe. They can double-back to touch home if they need to (and as long as they can avoid the tag). Similarly, if the runner doesn’t touch home and also the fielder misses the tag, both parties can Looney Tunes their way around until a final call can be made.

But— with the ball/runner/fielder all converging at the same place at the same time, MLB has implemented some additional rules designed to prevent nasty collisions². These rules have at least slightly reduced the number of wrecks at the plate, but we’d be lying if we said they were clear, and that lack of clarity has led to an awful lot of arguing (and calls being overturned on replay) in the ensuing years.

Both the runner and fielder have a responsibility to avoid unnecessary collisions. For the purposes of the rest of this section, we’ll say that the fielder is the catcher, though it doesn’t have to be. Now, a runner headed for home plate already has a fairly wide swath of territory they can use to travel to the plate; they don’t have to stay within the dirt of the base path, and instead many will take a curved path that takes them into foul territory³. And as long as they don’t suddenly juke towards the catcher as they near the plate, that’s all well and good. If they do deviate towards the catcher, they can be called out for interference. Similarly, if the runner does collide with the fielder, and the umpire judges that the runner had a path to slide that could have avoided said collision, the runner can be called out.

The fielder, meanwhile, is not allowed to completely block the path to the plate unless they have possession of the ball, or if they’re trying to catch the ball as it’s thrown in. So, as they’re waiting for a throw, they should, in theory, give the runner a lane to use to get to the plate. It doesn’t necessarily be a generous lane, mind you, but it does need to exist, and it’s up to the runner how creatively they’re going to use it. Sometimes, it can be pretty darn creative. If the umpire judges that the catcher is blocking the plate illegally, then they can call the runner safe. However, if the catcher isn’t actively hindering the runner, or if the umpire judges that the runner would have been out even if the catcher had not blocked the plate, they can still call the runner out.

If there isn’t any drama, however, the ball will stay live (unless the play at the plate resulted in the third out of the inning), and the catcher can potentially attempt to throw out other baserunners who might be trying to take an extra base.