The middle hitter is usually the best blocker and quickest hitter. This way you have the opportunity to have a really good blocker on both ends of the net as well as in the middle.
The middle hitter doesn’t always play in the back row. Most often the Libero will sub in for them. However they still serve most of the time.
The middle hitter's base position is in the center of the net, between the outside hitter (OH) and the right side hitter(RS).
The middle is often the tallest player too, but not always.