Even at the Little League level, where more players are likely to be ambidextrous, the same rule applies. According to Little League Rule 8.01(f), the pitcher must show the umpire, hitter, and runners which arm he/she will throw with, and the pitcher cannot swap arms during that at-bat and receives no additional prep or warmup time. The purpose of this rule is to even out any advantage one side over the other might have due to their arm being stronger for some reason (i.e., dominant hand). There is no real disadvantage to this rule, as both sides can use all fields, but there is a practical limit as to how many batters a player can face without changing pitchers. Little League Baseball has not announced any intention to change this rule.