"It's becoming one of the great mysteries of Chicago sports: Why is Jay Cutler getting worse when he's supposed to be getting better?

There are all sorts of plausible theories: He plays behind an average-at-best offensive line. He has an unproven group of Nos. 2 and 3 wide receivers. He's playing in a system that subjects him to too many direct hits and sacks. He has a high ''Jeff George Quotient.''

As Lovie Smith would say, it's probably a combination of all of them. The Bears' offensive line is inexperienced at key spots and hasn't played together long enough. The Bears' receivers aren't as bad as some would think, but Greg Jennings and Co. just showed us what good really is.

Then again, Cutler played for Mike Shanahan with the Broncos, was sacked only 11 times in 2008, had a Pro Bowl receiver in Brandon Marshall — and still was 16th in the NFL in passer rating (86.0) with an offense that was 16th in points (23.1 per game) and finished 8-8."