This is one of the baseball throwing drills we use at the beginning of practice to jump start the players. It is a fast paced drill that works equally well for throwing and catching.
Zipper drill
Line up in pairs about 20 feet apart and the person next to you about 10 feet apart. The person on the end corner throws diagonal to the partner of the person next to him.
This player then throws to his partner across from him who then throws diagonal again and keep doing this until you reach the end of the line.
The person at the end then throws all the way down to the end (this is usually my catchers) to start over again. Repeat over and over.
When they have mastered this add the baseball. We try to get 3 or 4 balls going at the same time. This puts a lot of pressure on them to catch and throw quickly but on target.
Important note: Make sure the player receiving the ball is calling out the player’s name who is throwing the ball to insure they are focused and don’t get hit with the ball.