One one of the scale a team can play all out to win, taking appropriate risks along the way.
On the other end of the scale, a team can play not to lose, and minimize any risks.
The Bills adjust between these two poles in inverse relationship to the opponent and the situation. The better the opponent and the more important the situation, the more the Bills play "not to lose". This ends up in actually losing in these situations. Against bad opponents in regular season games, we are pretty good at usually (not always) pummelling the bad teams. This second situation contributes to the gaudy favorable stats in the first post.