I'm the other way around with this weekend's games.
31 of the Swans' 38 games at the MCG have been larger than 28k. Include Docklands and it's 65 of 80 games. 28k would be their lowest crowd against a 'big 4' team at MCG/Docklands ever. If you're a bigger team and you fail to get 30k against the Swans it's a poor crowd no matter what.
On the other hand, before Geelong started their run at the top mid 40s was standard for Collingwood-Geelong. It's difficult to find comparable games given both clubs spent nearly a decade in finals at the same time and together produced what I think is the greatest run of crowds in the history of the game from 2007-2012.
But from 1998-2005 (where quite neatly usually one of the teams was good and the other not) in Melbourne the crowds go - 44k, 34k, 50k, 65k, 43k, 45k, 50k, 48k. So I think mid 40s is still clinging to reasonable, even if it's sitting at the low end of that scale.
I take your point about the scarcity of sub 30K crowds for Sydney but to be honest Manic I truly believe that in the short to medium term Carlton is in real serious trouble.
It is a big club, an elite club and no one in his right mind thinks otherwise. We all know that there are Carlton fans in every office factory and shop in Melbourne and they would be back given the motivation but where is it coming from?
I detect a real deep demoralisation in their fanbase. They don't accept the rebuilding guff. They see year after year of awful stuff served up. They seem resigned rather than angry. We had it for ages at Richmond. That sense of just knowing that your club is drifting onto the rocks. It is hard to change course and hard to motivate a crowd.
You are almost always closer than most in your predictions but I will be amazed if they better 28K.