Our guest contributor is back to scout the enemy with his third and final preview of the Packers' NFC North rival teams, this time looking to the East and giving his opinions on why Matthew Stafford is actually hurting the Lions offense instead of helping it.

Editor's note: our thanks to Paul for his series of previews on the Packers' divisional opponents. See his work on the Bears and Vikings also.

Of the two biggest changes the Lions made this year, the more important is almost certainly Jim Caldwell replacing Jim Schwartz. Caldwell brings with him a reputation as a quarterback guru, and Detroit is collectively hoping his staff can turn around one of the most undisciplined and - let's face it - hilarious teams in recent football memory. It's not just that the Lions collapsed last year. It's not just that they perennially fail to live up to the hype created by their big name stars. It's that no one seems to fail quite like the Detroit Lions. From fumbled snaps to frequent unnecessary roughness penalties to baffling interceptions and incredibly ill-timed fumbles in the snow, the Lions under Schwartz more often than not went out of their way to lose.

Defense

It's easy to blame this kind of thing on the head coach and I understand the hope that things will improve in a new regime. Coaching changes do matter and discipline can matter. Few doubt that working under Tom Coughlin is different than working under Lovie Smith. The problem as I see it for the Lions is that I believe some of their players are simply bad people. Compounding the problem, they are frequently difficult-to-bench bad people. Ndamukong Suh and Nick Fairley help to make up one of the stoutest defensive lines in football. They are also people who have shown a tendency to fly off the handle and stomp on opponents. You can attempt to impose discipline on them, but that often means taking them off the field, which makes the Lions much worse in terms of the talent on said field. It's a bit of a catch-22.

Discipline aside, the Lions boast what was by far the best defense in the division a year ago - they were the only unit in the NFC North that finished better than 25th in Football Outsiders' DVOA (they were 14th). They were not without their weaknesses (see this post from last season), but they were extremely stout against the run and fair against the pass most of the time. If Rashean Mathis is still a prominent member of the secondary they may struggle in that area, but there is some young talent that may develop (Darius Slay) and their front seven is capable of covering for a lot.

Furthermore, they were one of the few teams in the North that could routinely generate some kind of pass rush without blitzing. When you consider that the three contenders in the 2013 NFC North all possessed good-to-great offenses (when healthy) and that, of the three only the Lions possessed any semblance of a defense, it is downright shocking that they collapsed. It's in their nature, as previously mentioned, but there's more to this story. Let's move on to what I like to call:

Offense: The Megatron Effect

Calvin Johnson doesn't get enough credit. That may sound insane as even the national media calls him "Megatron" and he is widely regarded as the games greatest receiver, yet it's entirely true. In football the hardest part about working with statistics is deciding who gets credit for what. There are so many moving parts that assigning blame and credit always requires some guesswork, and we tend to default to the idea that on offense the quarterback deserves most of the blame and most of the credit. Generally speaking this is a good idea. The problem is that every so often you run into a situation like the Detroit Lions.

In his last 3 seasons Matthew Stafford has started all 16 games and averaged 403 completions, 680 attempts (59.2%), 4808 yards, 24 TDs and 18 picks a year. In 2010 Stafford missed most of the season. The Lions saw Shaun Hill and Drew Stanton start 13 games in his absence. If you combine their numbers and project them out to a full 16 game season, Shrew Stanhill had 401 completions in 658 attempts (61%), 4266 yards, 24 TDs and 18 picks. Consider also that Shrew, the definition of a replacement level quarterback, was playing with a still developing (but very good) Johnson while Stafford has had peak-Megatron. While these numbers superficially look pretty good, you can make a strong case that given the level of support in Detroit that Stafford has been barely (if at all) above replacement level. That's the effect that Calvin Johnson can have on a team.

Story continues