Leagues allow you to compete on a weekly basis with other players from all over the world.
There are currently 13 divisions that make up a league, from Rookie to Legend. In order to make progress through the divisions you will need to win coins from races. These coins will accumulate over the week and contribute to your rank. Only coins you win from races will count, and coins from the store and crates do not count.
Only players in the promotion zone of your division will get promoted to the next division. Be sure not to fall into the demotion zone otherwise you will be retrograded but remember that you can be in-between zones and remain in the same division from week to week.
Top ranks will give you a crate reward at the end of the league, and better divisions will give you more assets in every crate.
Leagues run every week from 1am PST Monday to the 1am PST the following Monday. After the weekly league has ended you will win a prize based on you rank and division.