Black Monks :
60 day running tally, so when a new one is played an old one drops off (remember in the past 48 hour gvg cycle and now a 36 hour gvg cycle is in place.)
Actually doesn't seem to be when new one is played old one drops off as our old one dropped off before the end of our current gc. So is purely time scale since the result, when it's been 60 days your result goes.
Which begs the question will it be out of 120 by the end of the next 60 days as we now get 40 gcs in that period as apposed to 30 in the last (if you were lucky enough to get matched up straight away, so probs actually only 29 or less as that never happened) but you get my drift.