Perception is a powerful thing in baseball. And for the vast portion of Oliver Perez‘s career, the perception has been that he’s an underachiever. He was a key pickup in the Brian Giles deal between the Pirates and Padres a decade ago, and for a brief moment, he looked like a future Cy Young winner. Perez went all Clayton Kershaw on the league as a 22-year-old lefty, whiffing 11 batters per nine frames and posting a sub-three ERA. But then, he lost his control, lost his fastball, and lost his major league roster spot. He turned into the Mexican Dontrelle Willis, basically.
Few may have noticed, but Perez has re-emerged as a quality reliever over the past two seasons. We may remember the walks, the injuries and the ill-fated $36 million deal with the Mets, but big league hitters will only remember his wicked slider. That slider could make Perez — recently signed to a two-year, $4.25 million deal with the Diamondbacks — a steal compared to other lefty relievers who commanded more cash on the free agent market.
Perez punched out 27.8% of the batters he faced over the 2012-13 seasons (ninth-best among lefties) thanks mostly to his slurvy, low-80s slider. Perez has induced swings and misses 46% of the time with his breaker, which is within shouting distance of slider aficionados like Greg Holland (47.1%) and Craig Kimbrel (52.3%). Lefties whiff more against Perez’s slider (50.8%) than righties (38.3%), but hitters on both sides of the play struggle to make hard contact (.296 slugging percentage for lefties, .250 for righties).
Admittedly, Perez hasn’t fooled batters out of the ‘pen as long as some of the other left-handed relievers who signed new contracts this winter. But you can make a case that he’s been as effective as more handsomely paid southpaws since the beginning of the 2012 season. His Expected Fielding Independent ERA (xFIP), which estimates how many runs a pitcher should have surrendered based on strikeouts, walks and a normalized home run per fly ball rate, falls right in line with J.P. Howell and Matt Thornton. Boone Logan has been somewhat better, but hardly enough to justify an extra $12 million-plus in guaranteed money.
Perception is powerful. It’s difficult to dislodge the memories of Perez striking out the side as a 22-year-old phenom in Pittsburgh, Bugs Bunny vs. Gas House Gorillas style, or the memories of him flaming out in Queens. But Perez is neither of those pitchers at the moment. Instead, he’s one of the better lefty relievers in baseball — and underpaid at that.