The high expectations for Gregory Polanco may trace their roots to comments Tim wrote on this very site more than four years ago, in advance of his breakout 2012 season at West Virginia. Since that time, Polanco has shown the flashes of superstar potential that excite both fans and scouts, but has yet to realize much of that potential at the major league level.
It’s worth noting that at 23 years old, Polanco delivered an essentially league-average season, with a .256/.320/.381 (94 wRC+) line that was a mild improvement from his 2014 numbers. Those upgrades were mostly due to increases in BABIP (.272 to .308) and isolated power (.108 to .125), rather than improved on base skills, since his walk rate actually declined from 9.6% in 2014 to 8.4% last season.
It was not, by any measure, a bad season for his first full year in the majors. But a new season brings new opportunities, and entering Wednesday’s game, Polanco was leading NL regulars in walks (10) and walk rate (27.8%). This led ESPN prospect expert Keith Law to quip the following during Tuesday’s game:
But wait, there’s more. The additional walks aren’t hurting Polanco when he decides to put the ball in play either, given his strong .281/.455/.438 line and 31.0% hard contact rate (career 28.5%).
By the eye test, this improvement in the young season seems to build upon some things we knew Polanco was working on with Jeff Branson last year, refining his approach in order to — and this should not surprise anyone who follows the Pirates — drive the ball to the opposite field gap.
That opposite-gap approach has been mentioned frequently by Pirates coaches, and it does fit with how pitchers have attacked Polanco in his young career: staying on the outer half of the plate and beyond, taking advantage of the larger strike zone for left-handed hitters. You can see the consistency of approach in these heat maps (from the catcher’s POV):
And here’s 2015:
The changes to Polanco’s process did lead to some improvements in the second half of last season. In July and August, Polanco had his best months for OBP (.363 & .380) and ISO (.152 & .170), and his second half contact profile had decidedly more hard contact than the earlier months of the season (32.9% vs. 27.7%). His outcomes on balls in play were not quite as strong in September as they were in July and August, but the quality of contact was broadly consistent with his previous success.
What seems to have changed at least somewhat for Polanco is what pitches he decides to swing at. Consider his swing chart from 2014:
As you can see from the chart, Polanco was definitely aggressive on the inner third of the plate. I would not say he was offering too much at pitches out of the zone, but there were certainly areas—particularly up and in—where he found himself tempted.
Now take a look at the first half of last season:
Here we start to see things shift a little bit. He is still susceptible to pitches up and in, but you can see that he’s swinging at a lot more at pitches on the outer third, and less on pitches down and in.
These adjustments continue into the second half of last season:
Now you can see that he’s being even more aggressive in the middle and on the outer third of the plate, while more selective on the inner third. This allowed for less pulled contact in the second half of the season vs. the first half (37.1% vs. 41.6%), and more contact to the middle of the field (38% vs. 33.2%), with roughly the same opposite field contact (24.9% vs. 25.2%).
From what we know from his nine games in 2016, Polanco is following an approach consistent with the changes he implemented last season, while also demonstrating — so far — a slightly more refined knowledge of the strike zone.
As you can see from the chart, Polanco hasn’t seen as many strikes this season (35.8% vs. 41.8% career), which can explain at least some of the increase in his walk rate. To his credit, he has been stubborn with not expanding the zone, having decreased swing rates over last year both outside the zone and overall (27.0% vs. 31% outside and 40.5% vs. 44.4%, overall).
He’s staying aggressive on quality pitches, slightly increasing his zone swing rate (64.5% vs 62.5% career) while keeping his contact rate mostly consistent with his career numbers. These are reasonably good signs that Polanco has learned from his experience, along with advice from the coaching staff, about how to look for quality pitches he is more likely to hit well.
A bolder analyst might say that with this greater selectivity and better contact profile, truly impressive results may be on the way. But these initial numbers are obviously based on tiny samples, and come with the usual caveat that things can change very quickly.
One need look no farther than Starling Marte’s production in 2013 (122 wRC+, 4.8 fWAR) as a tantalizing example of what a player can do in his age-24 season. It does seem that this calculated aggressiveness, which we know has been a work in progress for some time, has the potential to pay those kind of dividends for Gregory Polanco this season.