On April 21, The Boston Red Sox held a 9-1 lead over their rivals, the New York Yankees, when starter Felix Doubront gave way to Vicente Padilla for the seventh inning. What followed was an complete and total bullpen collapse of epic proportions. Padilla, Matt Albers, Franklin Morales, and Alfredo Aceves combined to allow eleven runs and the Red Sox lost 15-9. By the end of April, the Red Sox bullpen had a 6.10 ERA and a 5.05 FIP, both of which were the absolute worst in baseball.
Eighteen days later, the story is completely different. Since May 1, the Boston Red Sox have had the best bullpen in all of baseball. Red Sox relievers have combined for 65 innings in the month, the third highest total and posted a 1.51 ERA, the best in the game. The turnaround is not all luck either. The Sox pen has the third best FIP in that time as well, at 2.74. The team has even been forced to keep two extremely effective relievers, Junichi Tazawa and Clayton Mortensen down in AAA Pawtucket due to the lack of options among their other relievers. Even without injured closer-to-be Andrew Bailey and struggling setup man Mark Melancon, Boston has once again found a way to assemble a strong group of relievers to keep them in close games and preserve wins.
The difference is a combination of improved performance from some pitchers and the addition of a few new faces. Closer Alfredo Aceves has settled in to his new role now and has struck out 16 and walked just four since that epic collapse against the Yankees. In fact in May, Aceves has nearly a clone of 2011 closer Jonathan Papelbon, with a 10.80 K/9 rate and just a 2.70 BB/9 rate, good for a FIP of 1.77 to match his 1.80 ERA. Vicente Padilla has become the go-to high leverage reliever after Aceves and he has responded with an excellent run in May posting a 2.57 ERA and a 2.39 FIP. Lefty Andrew Miller has become more than just a LOOGY for Bobby Valentine since being called up earlier this month. While he may not maintain his fantastic 1.42 BB/9 rate, he is now matching his big time strike out ability with better control and he looks to be emerging as a quality late inning reliever at long last.
The biggest surprise however has been Scott Atchison. After spending his career as a spot starter and mop up guy, Atchison has been anything but a replacement level arm so far this year. His season ERA is just 1.13 and that is backed by a 2.51 FIP. Bobby Valentine has learned to trust him this month, giving him the ball more than anyone else in the pen with 11 2/3 innings in May. Atchison has responded by holding opponents scoreless in those innings, thanks largely to his miniscule 0.77 BB/9. Atchison is almost certainly pitching over his head, but he also appears to have improved his groundball abilities and combined with his control, that makes him an excellent bullpen arm and someone deserving of his current workload.
While this is an extremely short sample, much of what is happening now appears sustainable. Aceves is throwing harder than ever before in his new role and the strike outs should continue to pile up for him. Padilla and Atchison are both getting some good luck right now, but they also have the control and strike out ability to remain quality late inning relievers for Boston. If Miller has indeed figured out how to repeat his mechanics enough to maintain some semblance of control, he will be setup man or closer down the road as his stuff is the definition of nasty. Combine these strong performances with the possibility of some new blood later in the year in the form of Bailey, Mortensen and Tazawa and the Red Sox most glaring weakness early on could wind up being a major strength from here until October.