Platoon system

The platoon system or two-platoon system, in baseball or football is the method directing the substitution of players.

Baseball

In baseball, a platoon is a method of sharing playing time, where two players are selected to play a single defensive position. Usually, one platoon player is right-handed and the other is left-handed. Typically the right-handed half of the platoon is played on days when the opposing starting pitcher is left-handed and the left-handed player is played otherwise. The theory behind this is that generally players hit better against their opposite-handed counterparts, and that in some cases the difference is extreme enough to warrant complementing the player with one of opposite handedness.

Strategy

Right-handed batters have an advantage against left-handed pitchers, as left-handed batters benefit from facing right-handed pitchers. This is because a right-handed pitcher's curveball breaks to the left, from his own point of view, which causes it to cross the plate with its lateral movement away from a right-handed batter but towards a left-handed batter (and vice versa for a left-handed pitcher), and because batters generally find it easier to hit a ball that is over the plate. Furthermore, since most pitchers are right-handed, left-handed batters generally have less experience with left-handed pitchers. A left-handed pitcher may also be brought in to face a switch-hitter who generally bats left-handed, forcing the batter to shift to his less-effective right-handed stance or to take the disadvantages of batting left-handed against a left-handed pitcher.