Umpire Mechanics

[Andy]

I've always been taught that holding up the hand to the pitcher should be used judiciously.

It you are doing it between every pitch, it soon becomes part of the background and has a better chance to be ignored.

Most pitchers will wait until the batter is set to begin their delivery. While this is not always true, the umpire can gauge this as the game goes on and stop the pitcher when necessary. This is also very dependent on the level of ball you are calling as well. As you move to higher levels, you should almost never have to stop a pitcher to allow a batter to get set. So when you do hold up your hand, it is a different sight and is more likely to be noticed.