After an exchange is completed, the teams shall alternate their roles such that the team that was the throwing team on the previous exchange shall become the receiving team, and vice versa. The throwing team shall choose the thrower for an exchange for the initial throw of the game. Whenever a player makes a good catch while his team is receiving, that player shall be the thrower on the subsequent exchange. If two players are equidistant from the throw and both fail to touch it, then the throwing team will decide which of the two players shall return the throw. Whenever the players on the receiving team fail to make a good catch, but do touch the disc during the exchange, the player who first touched the disc shall be the thrower on the subsequent exchange.
Fouls occur whenever the thrower steps on the line before or during the release.
Fouls shall be called by a designated player of the throwing team as they occur. The player designated shall be located on one end of the foul line to provide a clear view of the position of the thrower relative to the line. The scoring zone is in effect a two-dimensional vertical plane, perpendicular to the field and intersecting the field at the goal line. A player shall not be required to leave the ground to reach a throw. By moving vertically, a player increases the height of his scoring zone.