Stats Corner: Can Pirates' bullpen keep escaping jams?
Manager Clint Hurdle leaned heavily on a deep, versatile bullpen during the 2013 season, with Pirates relievers tossing the fourth-most innings pitched (545.2) and compiling the third-best ERA (2.89) in the majors. The Bucs' pen returns virtually unchanged in 2014, but Hurdle shouldn't count on those guys locking down the late frames so effectively as his club chases back-to-back playoff appearances for the first time since 1991-1992.
While many Pirates relievers had sparkling ERAs, several didn't strike out batters and limit walks at a clip suggesting sustained dominance. Justin Wilson, Tony Watson and Vin Mazzaro, in particular, escaped jams by stranding an extremely high percentage of base runners — something sabermatricians have shown to be more the product of luck than skill.
Pitcher Strand rate
Justin Wilson 84.9
Tony Watson 80.7
Vin Mazzaro 78.6
MLB Avg. for RP 75.2
Most relievers, even legendary ones, strand between 75 and 80 percent of players reaching base. Wilson's and Watson's 2013 strand rates were higher than the career mark of all-time saves leader Mariano Rivera (80.5 percent), and those lefties plus Mazzaro topped runner-up Trevor Hoffman (76.7 career stand rate).
If Wilson, Watson and Mazzaro can't continue the Houdini act, their ERAs could spike in 2014. ZiPS, a projection system available on Fangraphs, predicts that Wilson's ERA will increase by over a run and a half this season. Watson and Mazzaro may cough up considerably more runs, too.