Diamond decay is too short
Decay in Diamond is too short. You have boosted d5 players and players who managed to get lucky who ruin the game for 4 other people by being in a rank they do not belong in. And they know this so they play one ranked game per month to maintain their D5 status without giving a care in the world how that game plays out, win or lose they'll be D5 at the end of the season.
I'm proposing that ranked decay in Diamond be shortened to once every 2 weeks to weed out those players. This wouldn't completely kill off boosting but it would make it really expensive for those players who get boosted to stay in Diamond. And the players who arent necessarily boosted would have to actually care about the quality of the game.