For all you Bears fans out there, I thought I'd do this public service. Everyone is talking about how bad the offensive line has been and about how poorly Jerry Angelo has drafted that part of the team - and everyone is right. But here's a breakdown that will make you cry.
(If you want to see all of Angelo's drafts for yourself, here you go:
2002, 2003, 2004, 2005, 2006, 2007, 2008 , 2009, 2010).

In the 9 drafts Angelo has conducted, he has picked a total of 11 offensive lineman. In 2004 and 2005, he did not draft any.
Of those 11, seven came in the 6th or 7th round and only 2010 7th-rounder J'Marcus Webb has really played.

His top picks were tackle Marc Colombo No. 29 overall in 2002 and tackle Chris Williams No. 14 overall in 2008. Colombo wound up hurt and released in 2005. Williams missed his entire rookie campaign due to injury and has already been moved to guard.

1993 3rd-rounder Terrence Metcalf was with the team until 2008 but could've been released long before then.

Through 8 years and 7 games of this season, Angelo's Bears have a:
66-68 record
11 drafted o-lineman (0 Pro Bowlers, 0 consistent starters)
(By round: 1st - 2; 2nd - 0; 3rd - 1; 4th - 1; 5th - 0; 6th - 1; 7th: 6)
3 winning seasons
2 playoff appearances
2 NFC North Division titles
1 NFC Championship
1 Super Bowl loss

Here is a look at 5 of the more successful NFL franchises in that time and their draft history with offensive linemen.

Indianapolis Colts:
103-31 record
12 drafted o-lineman (0 Pro Bowlers, 6 consistent starters)
(By round: 1st - 0; 2nd - 2; 3rd - 0; 4th - 3; 5th - 2; 6th - 3; 7th - 2)
8 winning seasons
8 playoff appearances
6 AFC South Division titles
3 AFC Championship appearances
2 AFC Championships
1 Super Bowl loss
1 Super Bowl victory

New England Patriots
101-33 record
11 drafted o-lineman (2 Pro Bowlers, 3 consistent starters)
(By round: 1st - 1; 2nd - 1; 3rd - 1; 4th - 1; 5th - 4; 6th - 2; 7th - 1)
8 winning seasons
6 playoff appearances
6 AFC East Division titles
4 AFC Championship appearances
3 AFC Championships
1 Super Bowl loss
2 Super Bowl victories

Pittsburgh Steelers
86-47 record
14 drafted o-lineman (0 Pro Bowlers, 6 consistent starters)
(By round: 1st - 2; 2nd - 0; 3rd - 3; 4th - 2; 5th - 2; 6th - 4; 7th - 1)
6 winning seasons
5 playoff appearances
4 AFC North Division titles
2 AFC Championships
2 Super Bowl victories

Philadelphia Eagles
85-49-1 record
15 drafted o-lineman (1 Pro-Bowler, 5 consistent starters)
(By round: 1st - 1; 2nd - 1; 3rd - 0; 4th - 4; 5th - 2; 6th - 3; 7th - 4)
6 winning seasons
6 playoff appearances
4 NFC East Division titles
4 NFC Championship appearances
1 NFC Championship
1 Super Bowl loss.

Green Bay Packers
78-55 record
15 drafted o-lineman (0 Pro-Bowlers, 4 consistent starters)
(By round: 1st - 1; 2nd - 1; 3rd - 1; 4th - 3; 5th - 5; 6th - 2; 7th - 2)
5 winning seasons
5 playoff appearances
4 NFC North Division titles
1 NFC Championship appearance

So what does all that mean?
It means that the Bears are clearly not an upper echelon team, but it shows that Angelo's notion that you can find lineman late is shared by some of the best teams in the league.

One difference is these better teams tend to draft - and hit on - good offensive lineman in the first three rounds.

The biggest difference is this: Teams, like the Colts, have found many starters in the later rounds - unlike the Bears. They know their system and what works.

And, it seems these better teams draft lineman in the 6th and 7th round as a total crap shoot - "hey, we might find a guy" but when they need to fill a key spot, they draft a guy higher. The Bears however, seem to load up on 7th rounders with the expectation that they will undoubtedly fill the key spot.