After each month, the accounts which finish in the top 10 should be added to a "hall of fame" and then permanently retired - the players are not allowed to come back with the same account.

The #1 winner should get blocked entirely, and shouldn't be allowed to create new accounts either, by policy. If the winner comes back and admits being an alt of their former winning account, it should be grounds for an immediate ban on the alt.

After a few months this should have the effect of clearing out some of the cabal/PGA/buddy relationships among the winners and give other players a better chance at first.