It is a carry over from all the years of baseball. My family still calls it the 'hill'. "Who's gonna be on the hill this game"? ( example )
Hard to break old habits.
Hard to break old habits.
Some people get wound up about calling the pitcher's plate "the rubber" or the pitcher's circle "the mound", but I can live with it. I suppose if I'm addressing a group of umpires, or explaining a specific rule, I'm more apt to use the proper rule book terms. In casual coversation, I might be more inclined to use the common, layman's terms as long as the person I'm talking to knows what I'm talking about.
If you really want to get somebody riled up, ask an umpire about his "clicker", instead of his ball and strile indicator! And yet, not too many umpires will bat an eye if you call home plate "the dish" or refer to the bases as "bags".
And since we have someone from the Great White North onboard...
What is up with the Canadian custom of referring to the catcher as "the back catcher"?