Ballers Keeper Rules?

Anyone remember how the Ballers do their keepers in their league of record? I’m interested in using that format in a league, but I can’t remember the exact specifics.

I think it’s something like:
1 definite keeper. Then 2 out of 3 keepers (from a different position than definite keeper) decided by lottery. So a total of three keepers with no penalty.

Here’s a more thorough explanation if I understand it right:

Pick 1 guy to definitely keep:
Example: Patrick Mahomes

Pick 3 guys you hope to keep (must be a different position than the definite keeper):
Example: Mixon, Dj Moore, Tee Higgins

Lottery happens where you end up with 2 of the 3 guys from the second batch:
Example: Dj Moore & T Higgins

Mixon and the rest of your team would go back into the redraft pool to be drafted at the beginning of the season.

There may be a 3 year limit in definite keepers but I can’t remember. The point is you could keep some guys, have draft pick trading, and still have it a bit fresh every year.

Hope this helps!

@DinosaurPete thank you for the explanation!