The Rays' success highlights a sabermetric point: Because the performance of individual relief pitchers, in their limited work samples, can fluctuate wildly from season to season, it's best not to invest too heavily in any but the very best of the class. The idea goes deeper than the math, however. Relievers often are in the bullpen because they're flawed, unable to master a third pitch or stay healthy throwing their first two. Often relievers having big years are maxing out both their effort and ability, making them poor bets to repeat at that level. You build a great bullpen by finding the next Joaquin Benoit—the righthander who anchored the eighth inning for the Rays in 2010 with a career-best 1.34 ERA—not by paying Benoit for his big year after the fact. Benoit has a 6.59 ERA for the Tigers in the first year of a three-year, $16.5 million contract.
The volatility of bullpens is affecting teams all over the league. The last-place Twins are the flip side of the Rays: They lost Jon Rauch, Matt Guerrier and Jesse Crain to free agency over the winter and have been unable to replace the quality innings they provided. The Royals' surprising competitiveness comes from an influx of young power arms pitching in front of closer Joakim Soria. The Rangers, Dodgers and White Sox thought their strong pens from 2010 would return, but injuries or ineffectiveness have crippled all three.
The Rays have built another good bullpen by chasing skills rather than last year's statistics. Closer Kyle Farnsworth (signed for a year and $3.25 million, with a team option for next season) walked one man in his first 17 appearances. Journeyman Joel Peralta, who had a 49-to-9 strikeout-walk ratio with the Nationals last year, has 15 K's in 19 innings and a 3.32 ERA as Farnsworth's setup man. Under Joe Maddon the Rays have had strong bullpens loaded with castoffs. Last year's—with Benoit, Grant Balfour and Randy Choate—was no exception. Maddon and VP of baseball operations Andrew Friedman have once again shown that you don't need big dollars to get small relief ERAs.
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