As a life long player, it is obvious to me which glove should be used in certain scenarios. A catcher uses a catcher’s mitt due to extra padding and a first baseman uses a first baseman’s mitt for a wider and deeper glove that is helpful for catching errant throws. However, if you take a look at the rest of the positions, you may see that they have significantly different sized gloves and webbing.
Infielders typically use gloves that are 11.25″ to 12.25″ with most of them being on the smaller side. This is because infielders typically need to have a quicker glove to hand transition of the ball so that they have time to throw out runners headed to the different bases. Traditionally, third basemen will have the largest glove in the infield as they will get the ball quicker and do not have to turn a double play as the second baseman and shortstop will.
Outfielders will have gloves that range from 12.25″ to 12.75″. This is because they need a larger surface area for softer catches and catches on the run. The length of the outfielder’s mitt also allows for a little extra distance when making a diving or sliding catch. Additionally, an outfielder’s focus should be on the strength and accuracy of a throw rather than how quickly it can be made. This is because an outfielder is usually throwing the ball a longer way than an infielder.
Pitchers usually have a glove that is 11.50″ to 12.00″. This size is large enough for them to hide their grip of the baseball but also be small enough to maneuver in their stretch/windup. A pitcher will not often need to make a rushed through so the focus is on comfort when on the mound.