I like to have our centers get into a group of three and begin with two players on one side with the other player about 8 meters away. At the end where there are two players one will begin as the center and one will begin as the center defender. On the whistle the center and center defender begin to push against each other. The goal is to control that imaginary line of scrimmage. Let the players battle for 12-15 seconds and then blow the whistle which signals the center to swim towards the third player who has been positioned 8 meters away. When the center arrives he will go immediately to the center defender position and engage the center. Both players will push for 12 – 15 seconds once again fighting to control the line of scrimmage. On the whistle the new center swims to the other end a