At the end of each week, the highest ranking players in each league are promoted to the next league tier (e.g. the best Bronze Tier players are promoted to the Silver Tier).
Players that finish in the middle will remain safe within their league tier, and will not be promoted nor relegated.
Players that finish near the bottom of their league leader board will be relegated to a lower league tier. Once a player makes it into the bronze league, they can never be relegated to a tier lower than bronze.