Orioles manager Buck Showalter is a little unique in his handling of his pen. They lead the majors in relief appearances of more than one inning with 106. The Cardinals have just 58 such appearances, although both Britton and Rosenthal have gone more than three outs six times. What Showalter prefers to avoid is using a reliever on two consecutive days, let alone three. Tommy Hunter, now with the Cubs, is the only Orioles reliever to appear in three straight days this year, which he did once. Showalter has used a reliever on consecutive days just 44 times; Cardinals manager Mike Matheny has used a reliever on three or more consecutive days 26 times and two or more 84 times, leading to some concern that he'll burn out the pen by October.Showalter is frequently complimented as being an excellent bullpen handler, and the above demonstrates some of the reasons why. He's fine with relievers working a little longer, but he doesn't want them to get overworked by pitching too often on consecutive days.
Using Baseball-Reference.com's invaluable Play Index, we can extend the search terms a bit. Since the 2011 season (Showalter took over in 2010, but you can't start the search in the latter part of that season), the Orioles are second lowest in using relievers in consecutive games. They're also second lowest in ERA in the times they do opt to use relievers on zero days' rest. In terms of using relievers after one day of rest, they're in the middle (18th) during that span (and again are second lowest in ERA). After two days of rest? The O's are 11th (and fifth in ERA). Talented relievers deserve plenty of credit, but Showalter's handling is also a big part of the success.
The O's again boast one of the best bullpens in the majors. They rank fourth in ERA (2.68), t-fifth in FIP (3.29), fourth in K/9 (9.05), 18th in BB/9 (3.27), sixth in HR/9 (0.71), sixth in GB% (47.6%), and fifth in WPA (3.61).