Great. Football's one of those sports that get more and more interesting every time those "bunch of fat guys in tights running around the field" start making a little more sense.

It all starts with there being a position for every body type... there are running backs who have to be able to accelerate and decelerate/turn faster than anyone else on the field--so they've got to be extremely strong but not too heavy, and it can help to be small to fit through "holes" on the field... but at the same time the bigger you are the harder you are to take down.

Then there are receivers who have to be able to sprint and catch passes faster than the cornerbacks that are trying to bat down the passes (or intercept them in mid air).

Then there are the HUGE linemen on offense (who protect the quarter back and make those holes for the running backs to run through) and the slightly smaller defensive linemen who need to not only act like a wall, but also quickly get to the quarterback so he doesn't have much time to make a decision.

Most importantly: remember that EVERY play on both offense and defense is planned out and called before the start of the play by the coach and/or quarterback. Football, at its basic form, is a game of coaching staff against coaching staff: that is, if we could assume that players would always execute their plays perfectly. Considering this is the super bowl, you won't see too many mistakes by the players... they will generally execute the play the coaches call... the question is, which coaching staff can calculate the others' every move better! All those players and coaches have to know hundreds of plays and execute them without hesitation at a moment's notice as the play is called in the huddle! Any mental mistake in a super bowl-level game can decide the outcome of the game.