Kitten ball, mush ball, diamond ball, indoor-outdoor, and playground ball are some of the progressions the sport has made. Starting as an indoor activity that began as an unintentional game, Softball has transformed into a sport that is loved and practiced by many. The origins of the game date back to 1887, where it started after Yale won a college football game against Harvard, an attendee, who watched the game in Chicago’s Farragut Boat Club grabbed a boxing glove and threw it over to a Harvard supporter, he, in return, swung a broom handle and hit it. George Hancock, a Chicago Board of Trade reporter, shouted “Let´s play ball”, and the rest is history.

Since the beginning of the sport, different variations have appeared involving playing rules, equipment, and the dimension of the playing fields. The first big change occurred in 1895 when the game was moved outdoors, a rulebook was implemented and different names appointed, finally adopting "Softball" as the official name in 1926, a term coined by Walter Hakanson. Before obtaining its permanent name, the game varied with the size of the ball used.

Some teams chose to play with a 12-inch ball, however, teams in Chicago continued to play with a 16-inch ball, this brought further challenges but allowed to play in smaller fields and even indoors. Players didn’t use gloves, they allowed the ball to bounce on the floor before catching it and received it with their chest before grabbing it with their hands. They also needed to establish different strategies when batting and playing because the ball got softer as the game progressed, this meant that it was harder to hit greater distances towards the end of the games.

Further regulations were established by different associations and governing bodies. The sport began to be recognized in all the United States and one of its biggest international push occurred during World War II when American servicemen started playing and teaching about the sport to those around. In 2011, the International Slow Pitch Softball Organization was formed.

There are several disciplines that make a part of Softball: fast pitch, slow pitch, and modified fastpitch.  Particularly, slow pitch “requires the pitcher to lob the ball underhanded with an arc that reaches a minimum height of 1.22 meters and a maximum height of 3.05 meters” (ISPS).  The official rules developed early on, and later defined by International Slow Pitch Softball establish that there were 10 players on the field, playing the positions of pitcher, catcher, first baseman, second baseman, shortstop, third baseman, and outfielders. Slow Pitch allows for 4 outfielders.

Slow Pitch is a popular sport because of its varied characteristics, an estimated over 40 million athletes play at least one game yearly.

For further reference:
https://www.lstoptours.com/blog/who-invented-softball
https://www.britannica.com/sports/softball
https://www.softball.org.nz/Softball+NZ/History.html
https://www.athleticscholarships.net/history-of-softball.htm