Catcher is a position played in baseball. The catcher crouches behind home plate and receives the ball from the pitcher. In the numbering system used to record defensive plays, the catcher is assigned the number 2 (see Baseball scorekeeping). The role of the catcher is similar to that of the wicket-keeper in cricket.

Positioned behind home plate (by rule the catcher is the only player who is allowed to be in foul territory when a pitch is thrown), the catcher can see the whole field, and therefore is in the best position to direct and lead the other players in a play. The catcher typically calls the pitches by the means of hand signals, and therefore requires awareness of both the pitcher's mechanics and strengths and the batter's weaknesses. In addition, because the catcher's job is to catch pitches which often come in at speeds exceeding 90 miles per hour, the catcher wears protective equipment including a mask, chest and throat protectors, shin guards, and an extra-thick glove. Because the position necessarily involves a comprehensive understanding of the game's strategic elements, the pool of catchers yields a disproportionate number of major-league managers, including such prominent examples as Steve O'Neill, Al Lopez, Yogi Berra, Mike Scioscia, and Joe Torre. Although sometimes considered entirely too wordy, former All-Star catcher Tim McCarver has used the same analytical skills he used to excel on the diamond to become one of the great sports broadcasting analysts of all time.

Throwing

Catchers virtually always throw with their right hand. Since most hitters are right-handed and thus stand on the left side of the plate, a catcher who throws left-handed would often have to avoid these right-handed hitters for most of his throws from behind the plate. Thus players who throw left-handed rarely play catcher. Lefty catchers have only caught 11 big-league games since 1902 and Jack Clements, who played for seventeen years at the end of the 19th century, is the only man in the history of baseball to play more than three hundred games as a left-handed catcher. However, some observers, including the famed statistician Bill James, have suggested that the real reason that there are no left-handed catchers is because lefties with a strong throwing arm are almost always turned into pitchers at an early age.

Defensive plays

The critical defensive plays of catchers, aside from managing the pitcher by calling pitches and catching the ball on all pitches, include:

1. Preventing passed balls and wild pitches. Although the pitcher has the responsibility to not throw erratic pitches, catchers must have enough mobility to field the passed ball or wild pitch appropriately to prevent base runners from taking even more bases.
2. Fielding high pop flies often hit at unusual angles.
3. Fielding weakly-hit fair ground balls (including bunts) in front of home plate to throw them to a base to complete a groundout or a fielder's choice play. The catcher must avoid hitting the batter/runner with the thrown ball in most circumstances.
4. Covering home plate on any play in which a baserunner attempts to score. The catcher is obliged to attempt to catch a thrown ball while preventing the runner from reaching the plate.
5. Preventing stolen bases by throwing to second base or third base to allow an infielder to tag a baserunner attempting to reach the base. A very good catcher at preventing stolen bases has a low stolen-base rate per game against him; a poor one has lots of stolen bases occurring while he catches. Even if a great defensive catcher deters all but the most effective base stealers, he keeps the double play in order by keeping a runner at first base.
6. Rarely, a catcher can make a successful pick-off throw to first base to surprise an inattentive or incautious base runner at first base. Even the attempt may cost the base runner a stride or two that may be the difference between reaching second base safely on a ground ball and being put out at second base on a fielder's choice play or a double play. This is also called a snap-throw. The catcher will make a snap-throw after receiving the pitch
7. Rarely, a catcher can go to first base or third base on rundown plays at those bases.