I noticed that Korea is only doing one big challengers event, with open qualifiers, seeding matches, group stage and finally playoffs. It's pretty straightforward and you get to see a lot of different matchups. I think the downsides are there are a lot of seeding matches and it doesn't really give teams that aren't clicking right now a chance to improve (e.g. in EU Liquid and Fnatic only qualified after the second challengers stage). Just wanted to get people's thoughts