The GLSML has been in existence since 1987. Originally, the league was divided into divisions based on teams’ location, but in 1988 it switched to a ranked format of two divisions involving 26 teams and has continued to grow since then.

In 2010, in order to encourage growth of softball at both the intermediate and entry levels, the GLSML divided into two halves: the Majors and the Minors. Today, the Majors comprises 3 ranked divisions involving 24 teams; the Minors comprises 3 ranked divisions involving 25 teams.

The GLSML season is typically 14 games long and runs from May to August. At season’s end, the top and bottom two teams in each division are promoted/relegated. There is also promotion and relegation between the Majors and Minors.

The GLSML is the only open league in the Greater London area, meaning that new teams are welcome irrespective of background or affiliation. Enquiries from new teams are welcome year round. Teams that wish to join at the Majors level are subject to evaluation.

The GLSML organises weekend tournaments during the season open to league teams across all divisions. The GLSML also sends representative teams to compete in the British Softball Federation‘s League All-Stars tournament in June. At the end of the season, the GLSML All-Star Day features players nominated by each team in a series of North London vs South London grudge matches.

For new players, the GLSML offers Development Nights on alternating Mondays in Regent’s Park, where those interested in learning softball are taught the basics of the game. The intention is to create a new team to compete in the Lastball tournament in August and to enter the Minors the following year. This has proved a fun and effective way to introduce people to the game. Since 2011, the GLSML have teamed up with BaseballSoftballUK to offer skills training nights every other Monday night for new and existing players.