It's like a really bad rugby game, when they make 50cm of ground and grind to a halt - all these little short, choppy rushes which are immediately aborted, and the clean running bits are few and far between. Also, the way that they immediately face off in pairs and bump each other is frankly silly. Quite apart from my profound lack of comprehension of its finer points, I honestly don't think American football is designed to be watched by anyone who's ever watched any rugby.