interesting the way we think the expansion is going to go, against the AFL method which seems to me to be about having a local derby in each state. GC Vs Bris, GWS Vs Swans, Freo Vs West Coast, Crows Vs Port.
I guess complicated by the strength of RL in Qld which demands > 2 teams, plus NZ, which i guess atm is the derby team for Melbourne, but which really should have another club.
Given that there is only 1 large regional city in WA, SA & VIC (Geelong) whereas in NSW, QLD & ACT there are 6 (Canberra, Wollongong, Gosford, Newcastle, Gold Coast, Townsville) it kind of makes sense.
The AFL is now played in 7 cities after expansion to 18 teams.
The NRL is currently played in 9 cities after expansion to 18 teams could be played in anywhere from 10 to 11 cities and after that with 20 clubs around 13 cities having the largest geographical reach of any major comp in Australasia.
It is unlikely that the NRL will ever have more than 1 team in Perth or Adelaide. I can see a time however far down the track when Melbourne has a second team.
So in terms of direct traditional 'derbies' you'd have in the long term:
WA/SA (Perth v Adelaide) - 2 games a season
Melbourne (2 Melbourne teams) - 2 games a season
NSW Regional Derbies (Canberra, Wollongong, Gosford, Newcastle) - 12 games a season
Western Sydney Derbies - 12 games a season
Eastern Sydney Derbies - 12 games a season
Brisbane Derbies - 2 games a season
QLD Derbies - anywhere from 12 to 30 games a season
NZ Derbies (Auckland, Wellington, South Island) - 6 games a season
Not counting other rivalry matches not based on geographic loyalties.
Could you imagine having 30 pure QLD derby games a year? It'd be like bringing the QRL back.