The Buffalo Bills reached an embarrassing low last season on the afternoon of Dec. 20, when Washington Redskins quarterback Kirk Cousins shredded Rex Ryan's defense with four touchdown passes and a 153.7 quarterback rating, the third-best mark against the Bills in their history.
Their ensuing two games, wins over the Dallas Cowboys and New York Jets to close out the season, brought better results on defense that Ryan has cited this offseason as a reason for optimism. However, the causes for the Bills' defense spiraling from one of the NFL's best units in 2014 to the mess that it became by mid-December, as well as what sparked the "Eureka!