On offense, the middle is considered a hitter, on defense, he is considered a blocker. He is often the third and last person to touch the ball in a possession. The middle is a key defensive player on the court. The middle is often moving from sideline to sideline and is usually pretty tall.
Players are transitioning from offense to defense as the ball goes from side to side, so the goals of the middle shift as well.
When on offense, the middle's jobs are:
When on defense, the middle's jobs are: