By any objective measure, the Tampa Bay Rays bullpen was terrific in 2010.
Rays relievers posted the lowest team ERA in the American League last season (3.33). Using
FanGraphs' fielding independent pitching (FIP), a stat that runs along a similar scale to ERA but strips out the impact of balls hit in play, the Rays ranked second at 3.76. The Rays' three best relievers and seventh-, eighth- and ninth-inning men, Grant Balfour, Joaquin Benoit, and Rafael Soriano, were all among the AL's top 10 relievers by Baseball Prospectus' expected wins added stat. No way the Rays win 96 games and their second AL East title in three years if not for the bullpen's knockout performance.
So when Tampa Bay's top relievers all became free agents at the end of the year, the Rays took stock of their roster and let them all go. And here's the crazy part: They did the right thing.