how many players needed for a championship to start?

Recently, championship sections opened for all variants. But some have yet to start. For example, in Catchup, there are currently 8 players registered for the random variant, and 10 players registered for the size 7 variant, but they have not yet started.

Does anyone know how many players are needed to trigger the start of a championship section?

The minimum was 20 at some point. Not sure if Richard lowered it. There was another thread with similar question a few months ago.

I remember a Morelli championship only having one league with 12 players. I'm guessing the limit is somewhere between 10 and 12 (unless it's adjusted per-game).