Bullpen has turned season around

One month ago, the Boston Red Sox were 4-10 and broken.

The offense was inconsistent and the rotation stumbled to a 5.75 ERA. But both of those problems figured to be temporary given the pedigree of the players involved.

The bullpen was another story. Alfredo Aceves had a 24.00 ERA through seven appearances. Mark Melancon was demoted after posting a 49.50 ERA in four appearances (11 earned runs in two innings), which included giving up five homers. Those were supposed to be the relief aces.

As a group, the bullpen had an 8.44 ERA through 14 games, as opponents hit .335.

Blowing up the lineup or the rotation felt rash. But clearly it appeared that the bullpen couldn't succeed with its current personnel. Perhaps Daniel Bard would move back to the bullpen. Maybe GM Ben Cherington could swing a deal. Clearly, something needed to change.

Except no major changes occurred, and since then, Boston's bullpen went from the worst in the majors to among the best. In the past 30 games, Boston relievers have a 1.86 ERA.

In that span, the bullpen has only two losses, both in extra innings. One of those went to Darnell McDonald. In fact, if you take out McDonald, the bullpen has a 1.61 ERA in the past 30 games.

The bullpen's turnaround has been the single most important factor in Boston's climb to .500. Consider the Detroit Tigers, who have gone 10-18 in that span thanks in part to a 5.69 bullpen ERA.

So what changed for the Red Sox? Everything and nothing.

The key personnel remained the same, save for the return of a pair of injured southpaws -- Rich Hill and Andrew Miller. The difference was effectiveness.

The change starts with Aceves. Over the past 30 games, he's posted a 0.96 ERA while appearing in half of Boston's games. After blowing two of his first four save chances, Aceves has converted nine in a row.

The biggest difference has been finding control while de-emphasizing his fastball. In his last 15 appearances, opponents are hitting .118 on at-bats ending in an off-speed pitch. That includes 0-for-15 with eight strikeouts on the curveball.

While Aceves has re-emerged as the rock of the bullpen, Vicente Padilla is the fixer. Of the 15 runners he's inherited this season, none has scored. Opponents are hitting just .083 with runners in scoring position. His overall numbers suffer from a .395 opponent batting average with the bases empty.

An unlikely setup man, Padilla has registered a hold in seven straight appearances. Over the past 50 years, the Red Sox record is eight straight by Hideki Okajima in 2007.

A month ago, Matt Albers and Scott Atchison appeared eminently replaceable and nothing more than innings-eaters. They've both been devouring innings ever since.

Atchison's 1.13 ERA is the seventh-lowest in the majors among those with at least 20 innings. He's gone 10 appearances (and 12 1/3 innings) without allowing an earned run.

Opponents can't touch his off-speed stuff, hitting just .153 on his slider/curve combo. He's become a reliable ground ball pitcher by keeping the ball down in the zone. Last year, 27 percent of his pitches were low. This season, that's up to 41 percent. As a result, his ground ball percentage has gone from 46 percent to 59 percent.

Albers has benefitted from the reintroduction of his curveball. Essentially abandoned in 2011, it has accounted for 11 percent of his pitches this season. Like Atchison, Albers is also keeping his sinking fastball low in the zone.

Hill and Miller, both of whom started the season on the disabled list, are the only key contributors who weren't on the opening day roster. Those two essentially filled the slots initially occupied by Mark Melancon, Michael Bowden and Justin Thomas.

The two southpaws have been surprise contributors, but for very different reasons.

Nothing Miller did during his minor league rehab assignment foretold his current success. He issued 14 walks in 11 innings in Pawtucket. But Miller is finally finding the strike zone and making people miss with his fastball.

Opponents missed on just 14 percent of swings on his fastball last year. That's up to 39 percent in 2012. That's in part due to a spike in velocity. It's averaging 94.2 mph, up from 92.4 mph in 2011.

Meanwhile, Hill made a rapid return from Tommy John surgery and hasn't missed a beat in the process.

His curve, which accounts for half of his pitches this season, remains one of the most devastating pitches against left-handed hitters. Since the start of 2011, lefties are 1-for-21 on at-bats ending in his curve. Nick Markakis picked up the lone hit on Monday. Overall, lefties are 3-for-26 with 12 strikeouts against Hill since the start of last season.

The presence of both southpaws has eased Franklin Morales's workload, which has increased his effectiveness.

Not only has the bullpen become Boston's strength, but the Red Sox might even have depth to spare. Junichi Tazawa and Clayton Mortensen combined for a 0.57 ERA, 16 strikeouts and no walks in their stints in Boston. Both have been just as dominant in the minors. Meanwhile, Melancon has a 0.56 ERA with 24 K's and 3 BBs in 16 IP at Pawtucket. Most importantly, he hasn't allowed a single home run.

Boston's offense is a long way from full strength and the rotation continues its uneven play. But the Red Sox remain in the hunt thanks to the bullpen's drastic turnaround.