The “butterfly effect” — no, not that movie with Ashton Kutcher — is a chaos theory term coined by Edward Lorenz to describe how seemingly small incidents can trigger major changes later in time. If a butterfly flaps its wings, the theory goes, it can set in motion a chain of events that lead to a distant tornado weeks later.
It might also help explain the peculiar quarterback matchup coming Sunday, when two former teammates will become the first pair of quarterbacks since the AFL-NFL merger to meet in a conference championship game after neither started in Week 1.