As the nation starts hyping Monday night's game at Soldier Field, I hope no one loses sight of why the Chicago Bears are 4-1 and a 6 1/2-point favorite over the Detroit Lions.

The Bears have outscored opponents 98-27 during their three-game winning streak. But in each case, a defensive touchdown (or two) has been responsible for breaking open relatively close games in the second half.

In Week 3, safety Major Wright's interception return increased a 13-6 fourth-quarter lead to 20-6 in an eventual 23-6 victory.

In Week 4, the Bears held a 17-7 lead over the Dallas Cowboys midway through the third quarter before Lance Briggs returned an interception 74 yards for a score on the way to a 34-18 victory.

And in Week 5, the Bears led the Jacksonville Jaguars 6-3 with five minutes remaining in the third quarter when Charles Tillman's 36-yard scoring return opened the floodgates of a 41-3 victory.

Those three plays make it fair to consider the Bears' defense the top catalyst of their current record. And how they've gone about it is equally clear.

As per his philosophy, defensive coordinator Rod Marinelli has blitzed on about 21 percent of opposing dropbacks, the fifth-lowest total in the NFL. As the chart shows, the Bears have done most of their defensive damage when sending a standard of four pass-rushers. For the Bears, the more players they can put back in coverage, the better.

It's worth noting that the Lions' offense struggled for much of last Sunday's game against the Philadelphia Eagles when faced with max coverage and minimal blitzes. Quarterback Matthew Stafford had 91 yards passing, and receiver Calvin Johnson only one catch, before the Eagles started blitzing in the fourth quarter and leaving Johnson in single coverage. If the Bears stay true to their tendencies, the Lions won't see many such opportunities Monday night.