Big Decision: Bears offensive line

Another in a series of important offseason issues facing NFC North teams:

Everyone and their sweet mother wants the Chicago Bears to upgrade their offensive line this spring. You've seen quarterback Jay Cutler sacked 148 times in his four years as the Bears' starter, the third-highest total in the NFL over that period, and you want an appropriate response from general manager Phil Emery and new coach Marc Trestman.

Here's the thing: As is often the case, the perceived problem is usually more complex than the realistic solution. The reality can be boiled down to two points: The Bears' offensive line wasn't the unmitigated disaster last season it appeared to be from afar, and the top candidate for replacement is the player with perhaps the most potential of the entire group.

It's true that the Bears allowed the eighth-most sacks in the NFL last season (44), but deeper analysis suggests their offensive line was a mid-range performer relative to other teams. Our friends at Football Outsiders rank offensive lines with analysis known as "adjusted line yards" for the running game and "adjusted sack rate" in the passing game. You can read the explanation for yourself. Judging offensive line play can be subjective, but the bottom line is the Bears' line ranked No. 16 overall in the league when the same parameters were applied to every team.

What that tells us is something that intuitively occurred to many of you anyway. The line is not solely to blame for the team's big-picture offensive issues in recent years. Pass protection is only one cause of sacks; poor route-running, holding the ball too long and other mistakes can contribute as well.

That's part of the larger analysis Emery, Trestman and offensive coordinator/line Aaron Kromer must make before finalizing offseason plans. Does the Bears' line need to be overhauled? Or just strategically tweaked?

As they consider their options, they'll also have to evaluate their personnel. It's complicated.

The Bears' best lineman -- right guard Lance Louis -- had ACL surgery in December. They had two linemen start all 16 games last season. Left tackle J'Marcus Webb played better than expected in 2012 but is hardly an elite player; Pro Football Focus (PFF) ranked him No. 46 among NFL tackles last season. Center Roberto Garza is a respected veteran leader but a below-average center, according to PFF, which ranked him No. 30 in the league last season.

Finally, right tackle Gabe Carimi was benched last season after a miserable performance in pass protection and spent some time at guard after Louis' injury. But he is probably the Bears' best run-blocker and is only two years removed from being a first-round draft choice. You would think that Trestman and Kromer will look for ways to salvage his career before moving on.

That leaves left guard, a position that is not difficult to fill either in second-tier free agency or in the middle of a draft. Here's the bigger question: Should the Bears spend a significant asset to find a new left or right tackle? Or both? As ESPN's John Clayton points out in the video, there are currently seven starting left tackles who are headed for free agency and the draft is deep enough that three left tackles could be taken in first 10 picks.

This will be a Big Decision, and one that is impossible to predict. The Bears have an entirely new coaching staff whose views of the holdovers could be much different than in previous years. In the end, however, a good offseason could at most bring three new starters to the offensive line. Will the Bears go that far?