Defense must maintain discipline

Did the Pittsburgh Steelers expose an Achilles' heel in the Chicago Bears' defense? The Steelers rushed for 190 yards in their Week 14 win over the Bears, and a quick review of Chicago's defensive statistics in the second half of the season shows it wasn't an aberration.

The Bears allowed only one of their first seven opponents this season to rush for more than 100 yards, but seven of their last nine opponents topped the 100-yard mark, as Chicago allowed an average of 116 yards per game during that stretch.

The Carolina Panthers are 8-1 when they rush for more than 100 yards, so the Bears need to do a good job against the run this week. A metric analysis shows that the key lies in the performance of the Bears' defensive line.