pokemon-showdown/README.md

Pokémon Showdown Seasonals

Pokémon Showdown featured a Seasonal Ladder every month. In order to keep the code clean, old seasonals are backed up and saved here.

Seasonals have two main parts of code, the format and the team making script. For each year, they can be found in formats.js and random-teams.js

In order to make a Seasonal work, you need to add the correspondent format in formats.js and the team making script with the correct name in random-teams.js

You can have a Seasonal to work with the regular Random Team maker, you just need to specify it in the formats.js in "team".

Read more about this ladder here: http://www.smogon.com/forums/threads/seasonal-ladder.3491902/