What is an plate umpire?

Answer 1

The umpire that stands behind home plate and has responsibility for the following calls (not all inclusive):

strike/ball,

out safe (on plays at the plate),

foul ball down first base foul line (up to the first base bag) the third base foul line (in two man crews),

foul tip,

dead ball on a struck batter,

infield fly,

batter interference and,

catcher interference.

He also is responsible for enforcing all all of the rules pertaining to the lineup (substitutions, pinch hitter, pinch runner, etc.).

Despite common mistake the home plate umpire is not necessarily the Umpire-in-Chief (UIC).