Stats Corner: Can Pirates' Polanco handle the heat in season's final weeks?
So maybe Gregory Polanco isn't Yasiel Puig — at least not yet. The prized rookie thrashed Triple-A pitching (a .945 on-base plus slugging percentage) and got off to a similar start in the majors, but a prolonged slump has dropped his OPS to .665. That's more than 50 points below the MLB average (.720) for right fielders in 2014.
Polanco isn't struggling in a way that you might expect from a 22-year-old with scant experience at the upper levels of the minors. Instead of swinging wildly or whiffing at breaking and off-speed pitches, Polanco is having difficulty squaring up major league fastballs.
Polanco is displaying a sharp eye at the plate, chasing fewer pitches outside of the strike zone (29.6 percent) than the MLB average (31 percent). He's also crushing breaking pitches, with an above-average run value per 100 pitches seen against curveballs (+2.03) and sliders (+0.2). But against fastballs, Polanco has the fifth-worst run value among 22 rookies logging at least 250 plate appearances.
Batter Team FB Run value
Kolten Wong Cardinals -1.10
Travis d'Arnaud Mets -0.91
Robinson Chirinos Rangers -0.80
Jonathan Schoop Orioles -0.80
Gregory Polanco Pirates -0.48
The Bucs' top prospect laid waste to pitchers who fed him breaking pitches early on, but now they're challenging him with heat. Polanco saw fastballs 55.6 percent of the time in June, but that increased to 59.3 percent in July and 64.3 percent so far in August.
Polanco isn't a Rookie of the Year candidate, but there's still reason to think he'll help the Pirates down the stretch. Polanco is projected for a .751 OPS during the rest of the season according to Oliver, a forecast system available on Fangraphs. That's well above Travis Snider's .687 projection, despite his recent hot hitting.