When a football team wins a game, how can they attribute all their success to skill? Isn't luck involved, too?

Think about it once. You often hear arrogant fans say, "Well, we were just better than you guys. It was all skill. We outplayed you and won." But to me, that's just ridiculous. Even when my team wins, I have to admit that some of the reason we won was because of luck. Hey, sometimes the fumble bounces right back into your hands. Sometimes the wind blows just the right way on the field goal. Sometimes an opposing cornerback slips and falls down which allows our receiver to catch a touchdown. I mean, isn't it a bit arrogant to say a win is always because of skill?