In baseball, a switch-hitter is a batter who is able to hit from both the right and left sides of the plate.

Switch-hitters are commonly taught to switch-hit at a young age, as learning to hit from the other side of the plate is often very difficult (but not impossible) to do after years of hitting exclusively from one side.

Usually, right-handed batters hit better against left-handed pitchers and vice-versa. So, a hitter who is competent from both sides of the plate can be an asset for a team and can cause myriad match-up problems for opposing pitchers and managers. This is usually one of three primary reasons many young players learn to switch-hit.

Secondly, a competent switch-hitter is less likely to be a part-time player. For instance, Rick is a right-handed hitter; Larry is a left-handed hitter. Both Rick and Larry are solid hitters, but they're also both first basemen who have difficulty playing other positions. The manager, knowing their defensive weaknesses, might choose to platoon Rick and Larry at first base. That is, having Rick start games only when the opposing starting pitcher is a left-hander, and only having Larry start games when the opposing starting pitcher is a right-hander. In this case, a first baseman who can hit from both sides of the plate would be a tremendous asset.

Thirdly, most curveballs, as opposed to screwballs, will break away from the hitter if he's batting on the same side of the pitcher, which is slightly harder to hit than if the ball is breaking towards him. A switch-hitter might hit from the same side a pitcher throws from in rare cases. Usually, it is either due to a pitcher historically dominating him, so the hitter might experiment by batting from the side the pitcher throws from to "throw off" or confuse the pitcher. A second reason might be because the pitcher throws the knuckleball, and the hitter feels that batting from the same side will give him a slight advantage. Of course, the theories on how to properly hit the knuckleball are incredibly varied.

Regardless of how well a switch-hitter can hit, he invariably hits better from one side as opposed to the other. Many switch-hitters often hit for a higher average from one side of the plate, yet have more power from the other. For instance, New York Yankees great Mickey Mantle always considered himself a better right-handed hitter, but he actually has more home runs batting left-handed. But it could be argued that this claim is misleading as many of Mantle's left-handed home runs were struck at Yankee Stadium, a park notorious for being very friendly to left-handed power hitters due to the short right field porch.

Switch-hitters tend to be overwhelmingly right-handed throwers, but there have been exceptions: Lance Berkman, Dave Collins, Doug Dascenzo, Mitch Webster, Wes Parker, Melky Cabrera, Nick Swisher and J. T. Snow (who in the final years of his career hit exclusively left-handed).

Baseball observers might find that the most successful switch hitters are natural left-handed hitters, but throw with their right hand. This is most likely due to the facts that a) since most pitchers are right-handed, a switch hitter who is a natural lefty can bat from his good side for the majority of the time, and b) a switch hitter who throws right-handed will have a strong right arm, so when swinging left-handed, their right arm, and stronger arm, is in front, so they will have a quicker, more powerful swing because the front arm is more important for power in the baseball swing.

Switch-hitters are also very rare among pitchers; notable switch-hitting pitchers include Mordecai Brown, Vida Blue, Norm Charlton, Sid Monge and Johnny Vander Meer, J.C. Romero, Kyle Snyder, Wandy Rodriguez, Troy Patton, Tim Dillard, Tyler Johnson, Carlos Zambrano. The pitcher Joaquín Andújar was the rare switch hitter who hit righty against rightites yet lefty against lefties.

"Switch Hitter" is the 29th episode aired of TV comedy series Arrested Development.