Offical strike zones-

Question
Where exactly is the official strike zone? I am a volunteer umpire and I get questioned about every other strike and ball calls.

Answer
Nathair,

Sorry for the delay in answering this.  I missed the email form all experts notifying me or your question.

The official strike zone for levels below college is the whole ball below the arm pits at the top of the zone.  At the bottom of the zone, it is the whole ball above the knee.  The sides of the zone it is any part of the ball over any part of the plate, including the black part.

It does not matter where the batter positions themselves in the box.  You make your judgement when the ball goes over the plate, not by the batter.

In practice many umpires will call the bottom of the zone when the top of the ball is at the knees.  The top of the zone, I call the whole ball below the letters.  On the sides a little off the edges will result in a strike as well.  

The most important part is developing consistancy.

Tom