At one point this season, the Chicago Bears were ranked among the top teams in the NFL. They're still pretty high up there, but they've now lost four of their last five games, and are 8-5 on the season. They managed to beat the Minnesota Vikings in Week 12, but just lost to them in the rematch on Sunday.
Why? Because they play the Bears next week, and they already beat them once, back in Week 2. Green Bay took home a 23-10 road win in that game, and another win over Chicago on Sunday would guarantee at least a tie in the division. And a tie would result in the tiebreaker going to Green Bay due to the wins.
The Packers have seemingly come up out of nowhere, after starting the season poorly. They've won three of their last four games.