As seen in CBell's video You Guys Can't Handle 2 Balls At Once, this plugin adds a second ball to the game. The orange team can only score the orange ball and the blue team can only core the blue ball. This only works in a LAN/Rocket Plugin match. Everyone needs the plugin for it to work. (well technically the clients can not have the plugin and just not be able to tell the balls apart.) If it's not working make sure everyone has loaded the plugin either through the plugin manager or through F6->
plugin load teammultiball. Have fun!