There is no black part of home plate. Home plate is white, and no other color.
Some home plates that you buy come with a built-in border that is commonly black. The black border has two purposes. First, it protects the edges of the white home plate so that they remain straight and don't get eroded/jagged. Second, it provides a sharp visual contrast to aid the umpire.
If someone says they are "giving the black," the translation is, "I am substituting my opinion on what the width of home plate should be for what is specified in the rule book."
No umpire has been granted such authority, but many claim it.
It usually takes a while, but strike zone threads eventually get around to someone saying why you don’t just call the zone as defined in the rule book or why is it that umpires have "their" zone and not the rule book zone.....
My zone is just what happens when I am behind the plate attempting to judge a 3 dimensional strike zone that changes based on the batters height. If you can imagine an invisible floating column, 17 and a half inches wide that extends from a horizontal line at the midpoint between the top of the shoulders and at the lower level is the hollow beneath the knee cap. The zone is determined by from each batters stance as the batter is prepared to swing at a pitched ball....the strike zone changes for a 5'6" batter to a 6' batter......
All of this adds to each umpire having their own zone....even as he may be trying to adhere to the rule book definition. It is just the reality of doing the job. I am known as an inside and low ball umpire. I know this from video tape of my cage work at umpire clinics. I am more apt to call a ball a strike inside and low than I am at the outside and high side of the zone. It’s just my reality...maybe it’s because I am shorter that I see that lower ball as a strike. I don’t know, and I’m not sure what I can do as a human to improve on that. I try and keep as consistent a zone as possible to avoid problems, but it is what it is. This is how I come to say what is defining "my zone" over the strict rule book zone....
Despite all our efforts, I feel there will always be some variance.......but I will try to get better......if at any time I feel I am doing "good enough" and fail to work on refining my game.....it’s probably my time to quit.
I hesitate to offer this statement since usually this is the child’s way out, but I will offer that it isn’t as easy as it seems.....If it was then anyone could do it, and over the years, I can confirm that many cant. Some develop an eye for it, the temperament for it, the patience for it and some never do.
Since I’ve admitted to having “my zone” I guess I am substituting my opinion on what is a strike for what is the “rule book zone. But I will take exception to one thing Midlo states and that is that NO umpire has been granted such authority.
The rule book absolutely gives us the authority. NFHS Rule 10 Art 4. Any umpires decision which involves judgment such as whether a hit is fair or foul, or a pitch is a ball or strike or a runner is out or safe is FINAL.
You may question the judgment of the umpire, but not his rule book given authority.