The last couple years the Indians have had a fairly average bullpen. Nothing special, but solid, not something that hurt the team either. That hasn't been the case in 2013, when things have changed, and not for the better. The Indians' margin for success is fairly thin as it is, because their lineup is good, but not great, and their starting rotation is improved, but still below average. Losing leads late and having close games get out of hand near the end of the game will be more than enough to sink the season, if it continues.
The Indians' bullpen has an ERA of 4.07, an ERA+ of 95. Those figures are worse than in the last couple years, but not dramatically. On the other hand, they had one of the best WPA figures in baseball over 2011 and 2012 (a combined total of 9.63, 4th best in baseball), but this year their WPA is -0.57, 22nd in MLB (WPA is 'win probability added.' It contextualizes events so that something that happens in the 9th inning of a tie game is more meaningful than the same thing happening in the 4th inning of a blowout). How do an ERA and ERA+ that are only a bit worse lead to such a big difference in WPA? The Indians' relief pitchers are doing a much worse job in tight situations than they were the last couple years (while doing a bit better when the game is practically determined already).
The pen already has 11 blown saves (6th-most in MLB) and has -0.3 fWAR right now, 4th-worst in MLB. What's led to such poor results? The pen is striking out a lot of hitters, and its batting average against, BABIP, and LOB% are all right around league average. What's done in the Indians' bullpen are walks and home runs. Their BB/9 is 3.86, 4th-worst in baseball, and their HR/9 is 1.22, 2nd-worst.
Lefties have been particularly bad, especially over the last month, when 9 of 25 appearances by lefties (36%) have led to multiple runs charged to the lefty, to say nothing of the runners they've inherited who've been allowed to score. League average LOB% is ~72%, meaning that on average, 72% of the bas runners on base when a relief pitcher enters the game will be stranded. 60% is considered awful. The LOB% for Cleveland's left-handed relief pitchers this year, along with their ERA+, to give you an added sense of how bad they've been (remember that 100 is league average and 80 is awful):
Take a minute to appreciate just how awful those figures are, 49.1 innings worth of disaster. There's a sense that every bullpen needs at least one lefty, but if these are the options, I say the Indians should ditch the southpaws entirely. They've signed lefties J.C. Romero and Clay Rapada in the last week, but Romero is already injured and there are reasons each of them was available in the first place.
While the lefties have been the worst, the most depended-upon righties (coming into the season) have also done poorly.
Chris Perez was doing well through the season's first few weeks, but he allowed runs in 4 of 5 outings in mid to late May, then landed on the disabled list with a strained rotator cuff. He was hit with drug charges during his DL stint and in what was expected to be his final rehab appearance Tuesday night in Akron, he was rocked for 5 runs while allowing 3 home runs, and now his return has been delayed while the team reassesses his health.
Vinnie Pestano has been the team's best relief pitcher over the last couple years, but he missed a couple weeks in May due to elbow tendonitis, and has struggled both before and after that absence. Fangraphs' Matt Klaassen has a nice, in depth look at Pestano's season, well worth reading. The short version: Pestano's velocity is down, but not much; most of his troubles come from walking more hitters and allowing more fly balls, with a high rate going for home runs.
Scott Kazmir has had a couple good starts, but all-in-all his results have been poor (his ERA+ is 65). When Zach McAllister or Brett Myers is ready to return, it might make sense to try Kazmir in the pen. Maybe he is the lefty they've been looking for??? Upon his return, Myers himself might be better suited for relief work too. His 3 starts this season weren't good, but he spent the previous two seasons as en effective reliever for the Astros and White Sox.
Whether it's one or both of those guys being moved into a different role, a recent signee coming aboard and making a positive impact, or the current guys just doing a better job, let's hope something improves soon. Good hitting and a starting rotation threatening to reach the dizzying heights of league average are nice, but they won't be enough if the bullpen continues to falter.