The Kansas City Chiefs are not a very good football team right now. As bad as they've been been, though, at least they haven't tortured their fans by blowing double-digit leads in every game. This battle of winless teams is currently going off with the Vikings a marginal 1-point favorite, but it opened with the Chiefs as a 3-point favorite.
The Chiefs are at home, so that is obviously what is accounting for at least the initial line, but stats appear to be overtaking emotions here. As bad as the Vikings have been, they've only been outscored by an average of less than five points, while the Chiefs have only played one remotely close game.
The over/under is sitting around 40 points, depending on where you look, but that would require one or both of these teams to display some offense otherwise unseen.