Injuries are my biggest holdup - although maybe an 18 game season would work if they added another bye week. Field conditions could be also an issue - and as the fields get more torn up late in the season injuries are more likely. Sorry TBC - but football is much tougher on a body than any other sport. Hits aren't the issue - players almost never get injured long-term from a "hit"... it's usually ligament or muscle damage from making a cut or from getting caught under a pile. In hockey you get hit and that's it - in football the impact is just the start, and is often followed by 3 people weighing as much as a light truck dragging you down and landing on top of you. No comparison.