The Baseball Economist: The Real Game Exposed by J.C. Bradbury

is gaining his left-handed bat in the batting order—nearly all left-handed throwers possess the valuable trait of batting left-handed. Lefties can play four positions in the field: all of the outfield positions and first base. All of these positions, except for center field, are considered to be easier to play than the infield positions reserved for right-handers. This gives a team three positions to stash even a defensively poor left-hander in the NL, with the DH as a fourth option in the AL. Unless a manager has an overabundance of left-handers on his team, it’s very unlikely that he will need the catcher’s spot to get a left-handed bat in the lineup, especially considering the fact that many right-handed fielders possess the ability to bat left-handed. For all non-catching fielding positions played from 1998 to 2004, left-handed throwers have manned those seven positions 24 percent of the time. This means that it’s the average baseball manager’s job to find a place for about two players (24 percent times 7 equals approximately 1.7 positions) to play among the seven positions in the field. Even after allotting three of those positions to right-handers only, the manager still has four slots to play lefties in the field without having to squeeze one into the catcher position.
    An outfielder has to be able to run and a catcher must have a good throwing arm, while first base requires the least amount of fielding ability on the diamond. The only real reason a manager would be tempted to put a lefty behind the plate is if he had a not-so-agile lefty with an excellent throwing arm and first base reserved for another player. This is a situation that very few teams face. There may be situations in the career of a left-handed player that would make his playing catcher a worthwhile move for the team to do at the moment. For example, a team has an up-and-coming lefty with a good bat, but he can’t run well enough to play outfield and is blocked by an injury-prone All-Star at first base. If he’s got a gun for an arm, you might consider putting him behind the plate just to get his bat in the lineup. However, the investment in training a lefty to catch probably isn’t worth the effort. Catcher is not an easy position to play, and it takes a toll on the bodies of the men who play the position. Why train a left-hander to catch when the odds are that he won’t have the role for long? The long-run returns to the player’s effort would be higher in working on other areas of his game, and the team would rather have its catching instructors working with long-run catching prospects. It’s just cheaper for the team to trade the player to a team without a logjam of players at first base, the traditional home for not-so-agile lefties.

The Simple Answer
    We could conclude that the main reason that there are no left-handed catchers is that there simply isn’t a need to use that position to get a left-hander playing time. Even though the advantage of being right-handed at catcher may only be slight, there seems to be no real cost to keeping left-handers out of the role. Using only right-handed catchers is like locking your car door in a small town with no crime. The chances that someone will break into your car are tiny, but the cost of protecting yourself against the small likelihood of the negative consequences is so low (pressing the lock button) that it’s still worth locking the door. Similarly, in those rare instances where the advantage of having a right-handed catcher is the difference between winning and losing a game—runner on second base in the ninth inning of a one-run ball game—you’ll be glad you have one.
    Even if we grant that there is an advantage in keeping opposing runners off third base for right-handed catchers, the advantage is very small. It’s small enough that a left-hander with an excellent arm could overcome it. But herein lies a second issue, which adds one more reason why lefties don’t catch. In