The Orioles' success in 2012 depended on a lot of things going just right. That included a weak year for the rest of the AL East, but plenty went just right for the O's themselves. Perhaps nothing was a greater example of that than the outstanding performance of their bullpen. Certainly, I think there's something to the notion that Buck Showalter did a great job of managing the 'pen that year, and some research agrees with that. And many of those guys simply had outstanding years: the '12 Orioles had five relievers pitch 55+ innings with ERAs below 2.65.
But, relievers are fickle beings, largely because of the inherently small sample sizes in which they pitch each year. Good results can easily mask poor peripherals, and vice-versa. And there were signs of regression to come as the year went on: Jim Johnson struggled during the playoffs, Pedro Strop fell apart in the second half, and the late-season reinforcements of Tommy Hunter and Brian Matusz had big platoon splits. On top of that, those five relievers mentioned above all had ERAs well under their FIPs - meaning that, based on their strikeout, walk, and home run rates, they would likely have higher ERAs over a larger sample.
All this is not to beat the dead horse about how "lucky" the team was in 2012, a theme which was played out a long time ago. The point is, the front office was - or should have been - aware that their bullpen could've used a little shoring up, but beyond the admittedly nice grab of T.J. McFarland in the Rule 5 Draft, Dan Duquette elected to stand pat as far as relief pitching was concerned.
There was a lot of speculation that this was because the O's didn't have money to go out and spend on anyone that would really be worth the investment. And in terms of starting pitching, that may well have been true, because good starting pitching is darned expensive. But as the season went on, the O's took on some salary via trades: Scott Feldman (~$2 million for two months), Bud Norris (~$1 million for one month), Michael Morse (~$0.5 million for one month), and Francisco Rodriguez (contract terms unknown, but likely ~$0.6 million for two months). That's a little over $4 million in salary that the Orioles took on as the season progressed.
Who else made a little over $4 million in baseball this year? No, not Tsuyoshi Wada - let's not even talk about that failed experiment. But Koji Uehara, former Oriole fan favorite, was signed to a $4.25 million contract in December of 2012 by Boston, and quickly became their best reliever (and, eventually, their closer). Imagine if Dan Duquette had pulled the trigger on Koji - who has been bizarrely underrated until finally getting some time in the spotlight with the Red Sox this year.
The Red Sox wouldn't have gotten their ace reliever, leaving their bullpen and search for a closer in flux. Meanwhile, the Orioles would've had an alternative for when Jim Johnson struggled, and wouldn't have needed to look to Brian Matusz or Tommy Hunter in less-than-ideal situations for their talents. They also would've likely held onto Nick Delmonico, rather than trade him for twenty-two innings of Francisco Rodriguez. And, as a bonus, Orioles fans wouldn't have to feel massively conflicted every time Uehara closes out another postseason victory for their AL East rival.
Obviously, I'm not arguing that signing Koji puts the O's in the playoffs. Even if it brought Boston down by a few games - not an outlandish notion, given that Koji was worth two to three wins according to WAR - things just aren't that cut and dry. Buck likely would've stuck with Jim Johnson anyway, as his reluctance even to turn to Darren O'Day during Johnson's struggles shows. The team was just too inconsistent this year, and cooled off too much in the second half, for one reliever to have made the difference. But, well, you never know... and when you're watching other teams, and former Orioles, in the playoffs, it's hard not to wonder what might have been.