Following a mapper allows you to create a feed of all the songs that come out for your followed mappers. If you have the SyncSaber mod installed, new songs from your followed mappers will automatically download in game when they are released. To follow a mapper, simply go to that mapper's page and click on the "follow" button.
You can get to a mapper's page by either searching for a map that they've mapped, and then clicking on their name:
Or you can go under the "Social" drop down menu at the top and click on "All Members" and then search for them:
If you choose "Mappers," it will only show approved mappers, so the mapper you're looking for may not show up there. In order for a mapper to be approved, they have to submit an application and have 3 maps that rank an 80 / 100 or above. This makes the "Mapper" section a great place to find proven mappers that are pretty much guaranteed to have fantastic maps.
If you have any questions about anything, feel free to join the Forum.
The forum lets you ask any question related to the site or Beat Saber itself and if someone from the community doesn't reply, one of the mods will shortly:
