you could get those natural regional rivalries if the NFL went to 17 games, removing 1 pre-season game. that 17th game could be a regional rival played at a neutral site, preferably like a college stadium. for instance, pitt-philly could be played in Beaver stadium, dallas-houston could be played at DKR, st louis-KC could be played at Mizzou, oakland-sf at the Rose Bowl and so on. only worry would be the teams from ohio and others that don't have a really natural rival. have to figure out some more with those, but you get the concept/