I've been reading "As They See 'Em: A Fan's Travels in the Land of Umpires", a book written by Bruce Weber about umpires and what it takes to become a major league ump (it's very good so far...at least after about 100 pages). But I read something I thought was interesting and had never heard explained before:
In the early days of baseball, home plate, like the other bases, was a square, and it was orientated so one point faced the pitcher, one faced the catcher, and the two others defined the horizontal limits of the strike zone. What has survived from this configuration is a bit of jargon that today is literally nonsense; that the plate has an inside and an outside corner.
I have heard announcers say during a game "that pitch caught the inside corner" or "a fastball on the corner for a strike" for as long as I've been a fan, and until I read that, I never realized the plate had no corners. Consider my mind blown.
Just thought I'd share that with you all.