Using the Basketball 2-1-2 Zone Defense
The 2-1-2 defense makes it difficult for the other team to score in the paint and around the key. It's a great defense to use against teams that have that type of offense as their strength.

Set-Up
Players 1 and 2 set up near the top of the key on either side of the free-throw line. Players 3 and 4 set up near the low post on either side of the basket. Player 5 sets up in the middle. Players 1 and 2 need to be fast and have superior ball-handling skills. Players 3 and 4 should be excellent rebounders. Player 5 should be a big, aggressive player.

2-1-2 Defense
Roles
Players 1 and 2 meet the point guard, keep the ball from entering the top of the key and prevent it from being passed. Players 3 and 4 keep the ball from entering the low post. They also go out and meet the ball when it's in front of them. Player 5 keeps the ball from getting into the paint.

This is a simplified explanation of roles. In reality, the players constantly shift in response to the location of the ball and what the offense is doing. Below are two common examples of how this works.