atm its not rly working cause 1 game is enough to not have any decay at all
AND we dont rly need decay – just make people have to play the game
so:
step 1
flag the account with status: inactive when not played 10 games in a month
step 2
dont show account on leaderboard when it has the status: inactive
step 3
to remove status inactive he have to make 10 games in a month (on his old matchmaking rating)
simple but atleast it would work
have a nice day