Baseball gloves are measured by starting at the top of the index finger of the glove and measuring down the finger, along the inside of the pocket and then out to the heel of the glove. Gloves typically range in size from (youth starter size) to for adult outfield play. Catcher's mitts, unlike those of other gloves, are measured around the circumference, and they typically have patterns. The shape and size of a glove are described by its pattern. Modern gloves have become quite specialized, with position-specific patterns: • '''Catcher's mitts''' are called "mitts" because they lack individual fingers, like mittens. They have extra padding and a hinged, claw-like shape that helps them funnel fastballs into the pocket and provide a good target for pitchers. Some catchers use mitts with phosphorescent paint around the ridges to provide a clearer target for the pitcher. In addition, catcher's mitts come in single hinge and dual-hinge varieties. If required to catch a
knuckleball, a catcher will typically use an even larger mitt. Some knuckleball catchers have even experimented using first baseman's mitts, as described below. • '''First baseman's mitts''' also lack individual fingers. They are generally very long and wide to help them pick or scoop badly thrown balls from infielders. These mitts usually have patterns, measured from wrist to the tip. Because first basemen are often left-handed, first basemen's mitts are readily available to fit on the right hand.
Hank Greenberg is often credited as the first to wear this style of the glove in the field. Some catchers, such as
Victor Martinez, use a first base mitt while catching knuckleballers, though doing so comes with a disadvantage: because first basemen are rarely required to make a quick throw to another base, first base mitts tend to make the task of catching
base stealers more difficult—a task already complicated by the knuckleball's slow speed and erratic behavior. • '''Infielders' gloves''', unlike the first baseman's mitt, tend to be smaller. They have shallow pockets to allow fielders to remove the ball easily in order to make a quick throw to a base. The webbing is often open to allow dirt to pass through the glove so that infielders do not pull out a handful of dirt when trying to remove the ball from the glove. Infielder's gloves typically have patterns. • '''Pitchers' gloves''' usually have a closed, opaque webbing to allow pitchers to conceal their grip on the ball (which, in part, determines the behavior of the pitch in flight) from the batter. Pitcher-specific gloves tend to have patterns; some pitchers such as
Gio González use gloves with patterns as large as . Infield gloves with intricate webbing are also used by pitchers.
Switch pitchers use a glove with six fingers. • '''Outfielder's gloves''' are usually quite long with deep pockets to help catch fly balls on the run or in a dive, and to keep outfielders from having to bend down as far to field a ground ball. These gloves typically have patterns, measured from wrist to the tip. They are frequently worn-in differently from those of infielders, with a flatter squeeze rather than the infielder's rounded style. •
Left-hand throw gloves are any of the gloves above, but designed to be worn on the right hand (for left-handed players). Players that utilize the left-hand throw gloves such as
Tony Gwynn or
Sandy Koufax are most frequently pitchers, first basemen, or outfielders. • '''Switch-thrower's gloves''' are gloves with a second thumb pocket on the opposite side of the glove, to allow it to be worn on either side of the hand. At the major league level, this glove has been used only by switch-pitcher
Pat Venditte. •
Sliding mitts were introduced in the 2010s as an evolution of earlier wrist guards that protect runners who slide onto base. ==Major glove manufacturers==