Field markings dictate player positioning during a face-off. A face-off is how play is started at the beginning of each period and after each goal. During a face-off, there are six players (without considering goalkeepers) in each of the areas defined by the restraining lines. Three midfielders from each team occupy the midfield area, while three attackmen and three of the opposing team's defensemen occupy each offensive area. These players must stay in these areas until possession is earned by a midfielder or the ball crosses either restraining line. Wing areas are marked on the field on the midfield line from each sideline. This line indicates where the two nonface-off midfielders per team lineup during a face-off situation. These players may position themselves on either side of the midfield line. During a face-off, two players lay their sticks horizontally next to the ball, head of the stick inches from the ball and the butt-end pointing down the midfield line. Once the official blows the whistle to start play, the face-off midfielders scrap for the ball to earn possession and the other midfielders advance to play the ball. If possession is won by the face-off player, he may move the ball himself or pass to a teammate.