Is the black part of the plate? This issue usually only comes up in a few circumstances.
- For pitches and how they relate to passing through the strike zone.
Technically, the strike zone is 17" wide and that is exactly what the white part of the plate should measure. So, no, in this case the black beveled edge shound not be regarded as "part of strike zone".
Now, for practical purposes this really shouldn't be an issue. The beveled edge of the plate, depending on how thick the plate is and how much of it is buried in the dirt, will be extended beyond the white maybe 1/4"- 1/2" on each side. I don't care who you are, or how good you might be, or what level of ball you're working- you are NOT going to be able to discern a less than 1/2" deviation in the path of a rapidly moving ball, as it relates to some imaginary three-dimensional object floating in space (the strike zone).
The strike zone is 17" wide, so is the white part of the plate and any ball that "nicks the corner" of the strike zone is a strike. The term "it caught the black" isn't based on some actual point of the rules that should be taken literally. It's really just a slang kind of way to say "that pitch just nicked the corner".
- In slow pitch softball to determine if a pitch hit the plate or not.
Okay, not too many people here might care about slow pitch. But, in that game, where a pitch hitting the plate is an automatic ball, it can be an issue. A pitcher might argue that the pitch hit "the black part of the plate" and thus did not hit the plate itself (which could, in theory, mean that it was a strike).
This one's been debunked by simple geometry. Given the diameter of the ball and the beveled edge of the plate, it is impossible for a ball to touch ONLY the beveled edge without also touching the white part of the plate.
Here, if the pitch physically "hit the black", then it had to have hit the white and can be regarded as having "hit the plate".
- For the purpose of a runner touching the plate while running the bases.
If a runner crosses the plate and somehow manages to just touch that tiny black edge, or if a runner slides in and touches the black, then she is considered to have touched the plate. The black edge of the plate IS part of the plate in this case. It is the side of the base, exactly the same as all the other bases have a vertical edge to them that the runner may touch.