Which sport was once known as "kitten ball"?

Softball is a game similar to baseball played with a larger ball. Despite the name, the ball used in softball is not soft, unless using a foam practice softball. It is about 12 in (about 30 cm) in circumference (11 or 12 in for slow-pitch), which is 3 in (8 cm) larger than a baseball.

George Hancock is credited as the game's inventor for his development of a 17" ball and an undersized bat in the next week. The Farragut Club soon set rules for the game, which spread quickly to outsiders. Envisioned as a way for baseball players to maintain their skills during the winter, the sport was called "Indoor Baseball". Under the name of "Indoor-Outdoor", the game moved outside in the next year, and the first rules were published in 1889.

In 1895 Lewis Rober, Sr. of Minneapolis organized outdoor games as exercise for firefighters; this game was known as kitten ball (after the first team to play it), lemon ball, or diamond ball. Rober's version of the game used a ball 12 inches (30 cm) in circumference, rather than the 16-inch (41 cm) ball used by the Farragut club, and eventually the Minneapolis ball prevailed, although the dimensions of the Minneapolis diamond were passed over in favor of the dimensions of the Chicago one.