Chicago has been able to play a ball-control style of offense because the defense has been fantastic, particularly up front. The Bears rank seventh in the NFL in total defense, 14th in scoring defense, 11th against the run, ninth against the pass, and Chicago hasn't allowed an offensive touchdown in its last nine quarters. Everything starts with Chicago's formidable pass rush. Former Saint Akiem Hicks has blossomed into a Pro Bowl-type talent for the Bears on the interior, and he leads Chicago with six sacks, but the Bears have also gotten edge pressure from Leonard Floyd and Pernell McPhee, who have four sacks apiece.
Meanwhile the Saints are without Larry Warford which won't help them deal with Hicks inside. The Saints opened up as 8 point favorites. That's a worrisome spread against a tough defensive match up. I'm not necessarily saying it's guaranteed doom or anything but it is something to think about.