In baseball, batting out of turn or batting out of order refers to an event in which a batter makes a plate appearance out of sequence from the batting order specified in the lineup card submitted by the manager to the home plate umpire before the start of the game. The initial batting order is a list of the nine position players selected by the manager to play that game, indicating the sequence in which they will bat and the position to which they have been assigned for the game. During the game, batters make a plate appearance in the order specified by the batting order, repeating the sequence once the ninth batter has made a plate appearance. Occasionally, one or more batters may bat in the incorrect order. In Major League Baseball, this violates rule 6.03(b) of the Official Baseball Rules. Batting out of turn is ignored by rule unless a member of the defensive team notifies the umpire that an infraction has occurred. Once the umpire is notified, the rule is enforced based on the official batting order. See Penalty section for the consequences of such notification. Determining the proper batter At any time, the proper batter is simply the player whose name follows the previous actual batter in the written batting order (at the start of the game, the #1 hitter is the proper batter, and in subsequent innings, the leadoff proper batter is the one who follows the last batter to complete a plate appearance in the last previous inning). Any batter's out-of-turn but completed plate appearance is legalized when a pitch is thrown to any subsequent batter on either team. Thus, in order to determine who is the proper batter at any given time, it is necessary only to consider the last two batters who have received a pitch—the last proper or legalized batter and the batter whose action will be nullified if found improper. When an improper batter is legalized by a pitch to a subsequent batter, the written order does not change. The proper batter is then the next batter in the written order just after the newly legalized improper batter, even if this causes one or more batters to be skipped. Because the umpire and official scorer are not to comment on the batting order (outside of ruling on an appeal), the teams need to be vigilant about following the written order.