They do. All the time. Not just at the end, but during the game if they make a good play, they'll point to the sky. It's insane. Sports and religion, especially American football and religion, are deeply intertwined in this country. It's one of the reasons I've never really gotten much into sports.
So I don’t think everytime to do the point to the sky thing it’s religious. I played a lot of sports through high school and in college and I did that but I’m an atheist. For me it was more of a “bless up” type thing. I’m sure a decent amount of it in sports is religious but I don’t thing every single time it is. It’s just a way to celebrate without being overly cocky and being proud of what happened
I think the way it works is one ascribes good things to Special Magic Jesus or his dad (same thing, I know) and bad things to The Satan. However, one team wins when the other loses, so somehow God made one team win and Devil made the other lose.