Okay, it's hard to explain, cause I'm making it up as I go along. Football is not a game of constant movement. It moves in fits and starts. The key to appreciating the sport is to understand what happens not only during the action, but between plays. The quarterback will attempt to give the ball to one of four or five different guys on the next play, and the defense needs to figure out who that's going to be. And every man on the field has a different role to play, moreso than in any other sport except baseball. I could go into detail about the intricacies of each position, but that would take forever. But it's fascinating to watch them play their position well. An offensive lineman, for instance, has two jobs: make a hole in the defense for a back to run through, or make an impenetrable wall around a quarterback. That's all he does. That's why they look like fatsoes. But they're actually brick houses.
This is hard to put into words. It's fascinating to see these giant men move and fight in unison. Some have likened it to war. I think that is apt. Every drive down the field is like a military campaign in miniature.
And I'm a sucker for rules. I like games with lots of complex, often counter-intuitive rules. Really, good management and an understanding of the complexity of the game plays a larger role in success on the football field than in other sports, except (again) baseball. I know that in hockey and basketball (which are really just variations on soccer, if you think about the rules and strategies) do rely on gameplans and teamwork, but only in broad strokes. In football, every play is carefully scripted on both sides of the ball.
Really, that's all I can say here. We'd have to watch a game so's I could explain it better. Trust me, it's magnificent.