The batting team wants to get runs. The batting team sends its players up to home plate in a special order. This order is called the "lineup". Each team chooses its lineup at the start of the game. After the game starts, the team cannot change the order. But the team can use a player who was not on the lineup. The new player has to change with an original player. The new player's name is written in the lineup where the original player's name was. After the ninth player has batted, the first player in the lineup starts again. If a runner comes to home plate, he scores a run. Then he is not a base runner. After scoring a run, the player must leave the field until it is his turn again. So a player can only score one run for each time he bats.