Softballs vary in size according to the type of softball game that is being played. There are three sizes: one for fast-pitch softball, one for slow-pitch softball and one for a style of slow-pitch play that is frequently called Chicago ball because of its popularity in that Illinois city. Gloves are not used in Chicago ball, and, generally, the larger the ball, the softer it is.
The 11-inch ball is used in fast-pitch softball. It is two inches larger than a baseball. The ball is fairly hard; however, the pitcher has a lot to do with how hard any ball is hit. The fielders wear gloves.
The 12-inch ball is the standard for slow-pitch softball. The ball is a little softer than the 11-inch version. The softness and its size, which makes it slightly harder to throw than a smaller ball, slows the speed of the game just a little bit compared to a game using an 11-inch ball. The fielders wear gloves.
The 16-inch softball is used when the game is played without gloves. This style of softball is quite popular in the Chicago and New York metropolitan areas. It is softer than both the 11- and 12-inch balls. Its size limits the distance it can travel compared to the smaller balls, and it tends to put a premium on quickness in the game over power.