The standard NFL TV setup could be used, along with blow by blow announcers, referees, and for really good moments the instant replay.
It could be fought out in quarters, with each side permitted a couple of timeouts, with a variation on capture the flag. Whatever side captures the other sides flag wins 3 points.
Whoever has the most points at the end of a few hours of brawling gets the prized Portland Cup.
During half-time there would be entertainment. 