What are 'single leagues' in fantasy football?
These are very rare, but single fantasy football leagues would be if you're just drafting from the AFC or the NFC. So basically it really limits your player pool. Maybe you're only familiar with the AFC, so that would be a single league draft. If you really wanted to get intense you could do a single divison draft. You don't really see single leagues or single divison drafts too often, but it might be something good if your friends get together and you're really just into the AFC, therefore you don't have to worry about the NFC and you just pick those players.