One of the most heavily discussed topics about the Bengals is their struggles defensively. Cincinnati’s wavering defense has uncharacteristically allowed 617 passing yards over the past two weeks: the most yards allowed by any Bengals team through two weeks. It’s ugly, and the team’s shortcomings have inevitably resulted in a plummet to the bottom tier of defensive rankings. A question worth considering: What are the odds of the Bengals defense actually emerging from the depths of defense rankings into a respectable standing by the end of the season?

Well, according to Paul Dehner of CBSSports.com, the outlook isn’t bright.

Dehner takes a look at teams over the last three years that began the regular season with a bottom-5 defense, and where each team ended their season in defense rankings:

2011

Tampa: 28/30

Arizona: 29/18-t

Green Bay: 30/32

New England: 31/31

Miami: 32/15

2010

St. Louis: 28/19

Jacksonville: 29/28

Detroit: 30/21

Houston: 31/30

Washington: 32/31

2009

Buffalo: 28/19

St. Louis: 29/29

Dallas: 30/9

Tampa Bay: 31/27

Houston: 32/13-t

For what it’s worth: Of the 15 teams listed above, three teams made it to the playoffs. The 2011 Green Bay Packers took a bye week straight to the divisional playoffs and of course the New England Patriots made it to the Super Bowl even with a defense ranked 31st to begin and end the season. The 2009 Dallas Cowboys were a Wild Card team that lost to the Philadelphia Eagles and never advanced.

Starting the season off with a bottom tier defense has not fared well for teams past. Mike Zimmer and his Bengals squad have an uphill battle ahead of them, and will need to fight to become the exception rather than the rule defenses have faced over the last three years.