Current system is fine imho.
"Players decay 25 points every 14 days of inactivity down to a limit of 2000."
Just add to inactivity "Games played with players 200+ points below your rate" and all rolls good again.
"Players decay 25 points every 14 days of inactivity down to a limit of 2000."
Just add to inactivity "Games played with players 200+ points below your rate" and all rolls good again.