Coming into the 2014 season, Pittsburgh outfielder Gregory Polanco was a top prospect with all the tools that make scouts drool — power, patience, contact, defense, and speed. He was Keith Law’s 13th-best prospect that offseason, and he played well enough in the spring to force himself onto the Pirates’ roster.
A good but not great debut, then just 22-year-old, showed hints of future glory, as his overall work compared decently to the debut from a young, toolsy outfielder named Carlos Gonzalez.
But Polanco has had difficulty capitalizing on that promise this season. And now, nearly 600 plate appearances into his major league career, the questions about his potential are getting louder, particularly his ability to hit for power and hit left-handed pitching. Using his appraisal of the situation and the statistics as a guide, maybe we can see if the shine has actually dulled on what was once star-level promise.
Through his first 574 plate appearances, Polanco’s walk rate (9.1 percent) and strikeout rate (19.5 percent) are actually better than the league averages (7.6 percent and 20.1 percent, respectively). His defense has rallied from a low point last year, and he has stolen 31 bases in 42 attempts. Those parts of his game are solid, especially for a player his age.
But for a player that had above-average power at every minor league stop above Class A, Polanco’s .109 isolated slugging percentage — about 25 percent worse than the league average — is worrisome.
At the heart of the problem is his ground ball rate. After posting a league-average 44 percent ground ball rate in the minors (according to Minor League Central), Polanco is hitting half of his balls on the ground in the major leagues. That sort of ground-ball rate limits your power upside.
According to Polanco himself, his difficulty is related to what pitchers are throwing him. “They are throwing more two-seamers, low in the zone, and it’s hard to hit it in the air,” Polanco told me before a game against the Giants earlier this season. While he’s right that pitchers have chosen to throw him the two-seamer more this year, the magnitude doesn’t appear to be huge. According to PITCHf/x, they threw him sinkers 24.4 percent of the time last year, and they’ve done so 25.2 percent of the time this year so far.
What has changed is the location of the pitches, and to Polanco’s credit, he has noticed. “They used to throw it in the zone — ‘Here, what can you do with this?’ — but now they know, and they are pitching me very tough. Tougher than last year.”
Part of this is the natural ebb and flow of adjusting to a young player. Hitters generally see fewer fastballs as they age, and if they show power, they start to see fewer fastballs down the middle of the plate. While Polanco isn’t seeing many fewer fastballs, their location is different. Check out the heat map of all pitches last year and this year and look for the missing red blotch:
Yup, they’ve stopped throwing him down Broad Street. Bill Petti created a metric called Heart Percentage, which measures how often the ball is thrown to the heart of the plate, and Polanco’s Heart% has gone down from 20.6% to 18.2%. That’s a top-30 decrease.
All of this comes to a head and becomes even more obvious against lefties. “They used to throw me inside because they know I have long arms, but I’m okay with that,” Polanco said of lefties. “I know I have quick hands, so I just trust my hands.”
If you look at the strike zone, you can see that while left-handers used to come inside and down the heart of the plate, they’ve decided to just throw him low and away now. Polanco just laughed when I asked about the fastball, low and away from a lefty.
And that nice hot zone he used to have inside? It’s gone now. Look at his isolated power against lefties. It’s gone.
So, what’s next? “Working on trying to get my pitch and not swing at the pitcher’s pitch,” Polanco said — “They’re always trying to get you.” His swing maps against lefties hold both good and bad news.
As the heat maps reveal, lefties are getting Polanco to reach and hit the low and away ball this year, at least more than last year. Contact with low-and-away pitches often lead to weak ground balls (and could explain Polanco’s elevated ground ball rate this season). The good news? Well, he didn’t swing at those pitches last year, so that restraint is conceivably still within him.
I could tell from talking with him, Polanco has a good head on his shoulders. He understands how it works: “They figure out what you can do, and then you have to figure out how you can hit the ball.”
For Polanco to return to showing the promise he had last season, he’s going to have to have more patience at the plate. He must avoid swinging at “pitchers’ pitches,” work counts and wait for balls he can hit in the air and drive. Fortunately in this case, the player understands what he needs to accomplish and he is saying all the right things. He knows he needs to adjust to the league, which seems to have already adjusted to him, and knowing that is the first step to fixing it.
With a phone full of pictures of pitchers' fingers, strange beers, and his two toddler sons, Eno Sarris can be found at the ballpark or a brewery most days. Read him here, writing about the A's or Giants at The Athletic, or about beer at October. Follow him on Twitter @enosarris if you can handle the sandwiches and inanity.