I don't think saying the Orioles are not having a good season is particularly audacious, but beyond bemoaning the team's record doesn't do much to explain why things are that way. One of the factors this year has been injuries: Brian Roberts has been out most of the year; Brian Matusz missed time and came back ineffective; Luke Scott has a similar story; and JJ Hardy was gone for a month. How significant have these losses been?
It's impossible to know for sure how these players would have performed if healthy, but a rough estimate using the pre-season projections should give a general idea.
That he actually played in 39 games was a surprise to me - it seemed like he's been gone pretty much all season. He didn't do much in his 178 PA (.221/.273/.331, 0.2 fWAR), and it doesn't look like he'll return this year. I had Roberts projected at 2 wins in 575 PA (about 133 games). At this point in the season, assuming an even distribution of missed time throughout the year, Roberts "would have" played 78 games and produced 1.2 WAR.
So, expected: 1.2 WAR from Brian Roberts in 78 games, plus replacement level production from back-ups.
Actual production at second-base: 0.2 from Roberts in 39 games; 0 fWAR from Blake Davis in 15 games; -0.3 fWAR from Ryan Adams in 9 games; and about 0.2 fWAR from Robert Andino in 50 games. That's a total of around 0.1 fWAR.
So if you want to pro-rate Roberts' actual 2011 production out to 78 games, the team has lost ~0.2 wins. If you give some credence to the projection (and thus assume that Roberts would have started playing better - not a stretch given his .236 BABIP), then the team has lost closer to 0.8 wins.
Matusz missed the start of the season, and then appeared to come back not at 100%; thus his 8.77 ERA and -0.5 fWAR. I had projected him for 175 IP and 3.2 WAR.
Expected: At this point it would be 103 IP and 1.9 WAR, plus replacement level production from back-up pitchers.
Actual: 25.2 IP and -0.5 fWAR from Matusz; let's say a month's worth of pitching from Zach Britton (assuming he wouldn't have been called up right away if Matusz was healthy to start the year), so around 42 IP and 0.6 fWAR; and the remaining 35 IP coming in a smattering from Tillman, Bergesen, Jakubauskas, and Atkins, at around 0.2 fWAR total. Overall that's around 0.3 fWAR.
Matusz's sucky pitching I think gets attributed to the injury in this exercise, so that's a loss of about 1.6 wins.
Luke's injury has likely had an effect on his performance even when on the field (like with Matusz). I had projected him for 2.1 WAR in 525 PA.
Expected: At this point it would be 308 PA and 1.2 WAR, plus a little bit in left-field and at DH (say, +0.1 WAR).
Actual: Scott has only 233 PA, and 0.1 fWAR. Reimold has been OK in left, but Pie has been so bad that the back-ups are like -1.3 fWAR. Vlad's at replacement level as DH, which makes that one easy. That's a total of around -1.2 fWAR.
So attributing at least some of Luke's poor production to his injury, this is a loss of around a win and a half (largely because Felix has been just so bad).
Hardy missed about a month at the beginning of the season, though I think that's largely forgotten due to his play since returning. I had him projected at 2 WAR in 525 PA.
Expected: At this point it would be 308 PA and 1.2 WAR for Hardy, plus replacement level production from back-ups.
Actual: Hardy is at 2 fWAR already, in 295 PA; Cesar Izturis and Robert Andino round out the rest of the playing team at around 0.3 fWAR. That's a total of 2.3 fWAR.
So this is a marginal loss; if you assume Hardy had played at the projected level during his time out, then downgrading from that to the back-ups is maybe a run difference. If he had played at the level he actually has this season, then it's a drop-off of 0.3-0.4 wins. But really, it was always assumed that Hardy would miss some time so this isn't really a big deal and probably has no relevance (if we're talking about results compared to expectations).
Add things up for these injuries, and you get around 4 wins (expecting ~4.3 WAR from second, left, and #2 starter, and getting -0.8 fWAR, though not all of the latter is due to injury). That would change the team's record from 39-56 (17 games under .500) to 43-52 (9 games under .500); still not good, but at least with some small sliver of hope of making a run and ending up with a winning season. There are still problems with the team, obviously, but the lack of depth plus starters missing time has definitely hurt.