Image via Flickr . Great football games are not decided by dropped passes. A game headed toward greatness that is ultimately determined by a drop is spoiled. This is unfair but true. Both the Baltimore Ravens’ loss to the Buffalo Bills in the divisional round of this year’s NFL playoffs, and the Bills’ own loss, one week later, to the inevitable Kansas City Chiefs in the AFC Championship, were potentially great games decided by memorable drops. Both catches would have been hard, and neither receiver disgraced themselves, but still. If the energy around this year’s Super Bowl matchup between the Chiefs and the Philadelphia Eagles is not what it should be, given a triumphant regular season, it is at least a little due to drops like these. In fact, these entire playoffs have felt like a dropped pass. To understand why, it helps to know something about the background of the teams that could have been playing this weekend, but are not, as well as the recent history of the big game itself.…