There's only one best-case scenario in the NFL: you win a ring.
Worst-case scenarios can go in a bunch of different ways. I've always preferred to save the best for last, so let's get the nasty stuff out of the way first.
The worst possible case for the Chicago Bears in 2013 starts with the possibility that hiring Marc Trestman to be the head coach was not the stroke of genius Phil Emery believes it was.
What if it turns out that there was a reason (or reasons) Trestman has been out of the league since 2004?
And what if it turns out Jay Cutler just doesn't have the people skills or just can't speak or understand enough NFL football to be all that he can be?
What about the offensive line?
J'Marcus Webb at any other position still could be J'Marcus Webb.
There is at least one reason, if not several reasons, that the Jets and Jaguars didn't want Matt Slauson and Eben Britton back.
Kyle Long will never have more than four starts in college before he plays his first NFL game.
Roberto Garza, hopefully, won't start to slip, but it's not likely he's getting better as he turns 34.
The Bears are paying Jermon Bushrod like an elite left tackle – he's good, not great – but he might find playing in front of Cutler a lot different than protecting Drew Brees.
And what if it turns out Martellus Bennett is no more than the journeyman tight end?
All of that would just mean the offense hasn't been fixed. But where things really could get ugly is if the defense that has carried this franchise over the past decade or more is no longer the dominant force it has been.
Brian Urlacher – the face of the franchise for the past 13 years – has retired.
D.J. Williams will be more athletic than the injured Urlacher was last year, but it's unrealistic to believe he can be the leader Urlacher was.
Israel Indonije was the Bears' second-best defensive lineman, and he's now in Detroit.
The Bears are counting on 2012 first-round draft choice Shea McClellan to emerge as a force, but if he doesn't, the Bears will struggle to rush the passer consistently.
For this defense to carry the Bears for stretches of the season, Julius Peppers, Lance Briggs and Charles Tillman will have to play like All-Pros. As each marches deeper into his mid-30s – see Urlacher's rapid decline – their ability to do that is a major concern.
Finally, injuries always are a concern.
This is a team with virtually no depth or young talent on the rise because of the failures of the Jerry Angelo regime in the draft.
Should either Cutler, Peppers or Briggs be forced to miss significant time with injuries, the Bears will have no chance of playing in the postseason.
The worst-possible case for the 2013 Bears is that all these things fail.
Fear that perfect storm, because if it happens, the Bears will be a 4-12 or 5-11 team.
Just for the record, I don't believe there's any chance the worst case will become reality.
There are a number of highly-respected NFL insiders that I've spoken with the past few months who believe Trestman is an offensive savant, and that Cutler has exactly what he needs to finally prove his genius.
Brandon Marshall is still one of the best wide receivers in the league, and Matt Forte and Michael Bush are as good a one-two punch at running back as you'll find anywhere.
While Bennett isn't special, he's a huge upgrade at tight end, and while the offensive line is unlikely to be special, it might be perfectly maleable to adequately accomplish exactly what Trestman wants to do.
Add in improvements by Alshon Jeffery and Earl Bennett, and these 2013 Bears could boast a top 10 offense and swap points with the best of them.
The defense will not be as good as it was in 2012 and probably wouldn't have been even if Urlacher, Idonije and Nick Roach were all back.
The defense scored nine touchdowns last season, and only one defense in NFL history has ever scored more.
But if another year of wear doesn't slow Peppers, Briggs and Tillman, each unit will still be anchored by one of the best in the game at their positions. Corey Wooton was the most improved player on defense last year, and he, Henry Melton, Williams and Tim Jennings are capable of having big moments.
I expect Sedrick Ellis to prove to be one of the biggest steals of 2013 in free agency, and I wouldn't be surprised to see him return to his Pro-Bowl form under Mel Tucker.
The defense will allow more yards and more points than it did last year, most likely will have fewer turnovers, and, almost certainly, won't score as many points. But it could very well be stout enough to win as many as 10 games.
One more cause for optimism is the schedule.
True, based on last year's performances, it appears to be a much tougher slate than 2012. But it doesn't include San Francisco and Seattle, which both beat the Bears last year, and you won't find Atlanta on it either.
Those are the only three teams in the NFC that I really couldn't pick the Bears to beat short of some miraculous fall off from those clubs. And it's quite possible the Steelers and Ravens, whom the Bears will face, could be looking at somewhat sub-par years next to what we've come to expect from them in recent seasons.
Again, I just can't see this team in the Super Bowl this year.
But if everything I've laid out goes right, it's not impossible to imagine the Bears in an NFC title game against the Niners, Seahawks or Falcons.
But much like a 4-12 disaster, I don't see it happening.