@ossobuco,
Personally (not that you or anyone asked) I can't see Bills beating the Chiefs. That's all the more reason to go with Bills as an upset over the undefeated consistent Chiefs.
All kidding aside, Chiefs (and any NFL team) can be beaten on any given day.
I really have no love for Smith, KC QB with only 9 TD while having 4 Int at that this stage of the season on an undefeated team. He doesn't float my boat.
Bills still dealing with their green (2 yr) QB Thad Lewis. Furthermore, QB rookie EJ Manuel is out on injury.