For a position player like Gregory Polanco, who debuted for the Pittsburgh Pirates in 2014 as a 22-year-old, it's important to keep making progress with regard to on-field development each season. Between 2014 and 2016, that's exactly what the young outfielder was doing at the plate.
Polanco's 2016 season was easily his best, as he produced career highs in wOBA (.331), wRC+ (108), Isolated Power (.205), home runs (22) and RBI (86) through 587 plate appearances. Entering his age-25 campaign, it wasn't outrageous to think he'd continue progressing as a hitter in certain areas.
Unfortunately, this year has looked like one big step back instead of yet another step forward.
Not Hitting 'em Like He Used To
Through Polanco's first 195 plate appearances this season, his production in just about every offensive category has taken a dip. If he look at the non-counting stats from above, it's clear to see the differences in his wOBA (.299), wRC+ (85) and ISO (.114), and based off the minor dip in his BABIP (.291 in '16, .283 so far in '17), he should feel fortunate after taking a peek at his batted-ball profile.
The below table shows how he's progressed since 2014 in line-drive rate (LD%), ground-ball rate (GB%), fly-ball rate (FB%), soft-hit rate (Soft%) and hard-hit rate (Hard%).
| Year | PA | LD% | GB% | FB% | Soft% | Hard% |
|---|---|---|---|---|---|---|
| 2014 | 312 | 19.1% | 49.5% | 31.4% | 21.2% | 24.3% |
| 2015 | 652 | 19.7% | 45.4% | 34.9% | 17.5% | 30.3% |
| 2016 | 587 | 24.0% | 38.8% | 37.1% | 18.3% | 35.7% |
| 2017 | 195 | 20.3% | 45.3% | 34.5% | 25.7% | 22.3% |
Seeing 2017 as the outlier in this set of data shouldn't be shocking -- the only category that didn't improve in each of his first three seasons was soft-hit rate.
The spike in ground balls and corresponding drops in line drives and fly balls aren't ideal, but the biggest problem is his quality of contact. After making considerable progress in his hard-hit rate, he's currently on pace to have his worst season ever in that category. And for someone with 20-homer pop, it's never good to see their soft-hit rate be the higher number of the two.
With fewer fly balls coming off his bat, it's important to maximize his production for that particular batted-ball event. With just three homers and an ISO that's nearly on pace to be a career low (.108 in '14), you could probably draw the conclusion that Polanco hasn't exactly done that, and you'd be right.
After posting a 162 wRC+ and a .412 wOBA on fly balls last season, he's currently sitting at just 47 and .241, respectively, this season. And judging from his quality of contact in this situation -- a 27.5% soft-hit rate and 29.4% hard-hit rate, which are both on pace to be career worsts -- it's hard to drum up optimism moving forward if these trends hold.
Not Being Aggressive in the Right Situations
One of the few positives we can draw from Polanco's 2017 season thus far is that his walk rate (8.7%) has remained strong, while his strikeout rate (14.4%) is much better than anything he'd done previously in the big leagues.
How much of a positive can it be, though, with a batted-ball profile like the one we just talked about? Not much, and while he has gotten more aggressive at the plate over the years, he's not doing it in the right situation this year.
The below table shows how his chase rate (O-Swing%) and swings inside the strike zone (Z-Swing%) have changed each year, along with the corresponding contact rates and how often he's seeing pitches inside the strike zone (Zone%).
| Year | PA | O-Swing% | Z-Swing% | O-Contact% | Z-Contact% | Zone% |
|---|---|---|---|---|---|---|
| 2014 | 312 | 27.9% | 60.8% | 63.9% | 88.3% | 42.2% |
| 2015 | 652 | 30.6% | 63.2% | 70.5% | 89.2% | 41.5% |
| 2016 | 587 | 31.0% | 70.1% | 66.8% | 91.5% | 38.8% |
| 2017 | 195 | 34.1% | 68.1% | 65.4% | 92.3% | 40.4% |
The most encouraging trend here had been the increase in aggressiveness on balls inside the strike zone...until this season, when his aggressiveness shifted balls out of the zone. Suddenly, a steep drop in his quality of contact numbers don't look so surprising anymore.
Now, there could be a number of factors in play here -- outside of a recent hot streak, Andrew McCutchen hasn't been the same at the plate, while losing Starling Marte to his 80-game PED suspension likely also added some pressure on Polanco to perform. Add in Jung Ho Kang's inability to get a visa in order to bring some much-needed power to Pittsburgh's lineup, and it's easy for any young hitter to potentially get a little too antsy at the plate.
For a team that's one of the least powerful in all of baseball, Polanco could've been the guy to pick up the slack based off what he did in 2016.
We typically don't want to see hitters rack up strikeouts, but it's something that should be acceptable in this case -- if Polanco is getting more aggressive within the strike zone instead of outside it. Doing so will allow him to have a greater chance of hitting the ball harder than he has so far this year, thus potentially increasing his chances for experiencing the kind of success we saw from him last year. If he's going to be swinging more often overall like he is this season, at least be doing it on strikes.
There's still plenty of time for Polanco to turn around this frustrating start and take another step forward as he continues approaching his physical prime, but it's just not looking good right now.