A Graphical Look At Gregory Polanco’s New Plate Discipline
The start of the 2016 season has been somewhat refreshing and somewhat maddening while watching the Pirates, which means it is a real baseball season. One of the most pleasant surprises, though, has been the blossoming of Gregory Polanco into the potential player we envisioned him to be. With his new 5 yr/$35M contract extension in his back pocket, it is evident to me that Polanco has taken a deep breath and just relaxed so far this season. The game is not too fast for him anymore.
Polanco’s plate discipline has gone through the roof at the early outset of this season. Although you hear “small sample size” beaten to death this time of year, plate discipline is one of the quickest metrics to stabilize, typically around 100 plate appearances. After this weekend’s slate of games, Polanco is over halfway there. No, he will not have a walk rate of 23% for the whole year, but let’s look at a few graphical charts to see what’s behind his dramatic improvement from his 8.6% BB rate last year.
First up is Polanco’s whiff chart (courtesy of Brooks Baseball’s page on Polanco) for his 2014 and 2015 plate appearances:
Keep in mind that this is from the catcher’s point of view, so Polanco would be standing on the right side of this box. As you can see, his whiff rate was in double digits for anything low in the zone AND high in the zone, a pretty dangerous combination to overcome as a hitter. He was guessing wrong and chasing a lot of bad pitches.
Now let’s look at the whiff chart for the outset of the 2016 season:
In the same eight zones that plagued him in his first two seasons, Polanco has started to slowly close the gaps, especially on the pitches up high and the ones low (both in the zone and out of the zone). You can also see that if a pitch is in the strike zone, Polanco is making some sort of contact so far this year, as he only has two whiffs in the zone to date.
So what’s the secret here? Is it just maturation? Is it that his development path is taking the next leap, as we forecast last year? Possibly, but Polanco is simply being pitched differently right now. He has adjusted to the league and now we’ll see how long it takes the league to adjust to him. For the most part, advance scouts are working off last year’s data, so the “pitch him low or high in the zone” reports are the ones being used. Take a look at his career plate discipline numbers from Fangraphs:
There’s a lot to parse through, but let me direct your eye to the second-to-last column of Zone%. These are the percentage of pitches that are in the strike zone during Polanco’s at-bats. That percentage is comically low, indicating that the league is basically throwing him slop and daring him to lay off of it, which he has so far, as evidenced by his 26.9% O-Swing% (outside the zone). But when a pitch is in the zone, his Z-Contact% (zone contact) is through the roof at 91.2%. To contrast, here’s the same plate discipline chart for Andrew McCutchen:
The charts for McCutchen and Polanco show that so far Polanco is a better contact hitter than McCutchen. McCutchen’s career Z-Contact% is three percentage points less than Polanco and hasn’t crested 90% since his 2010 season. Additionally, on pitches out of the zone, McCutchen’s contact rate of 58.4% is far lower than Polanco’s 65.5%. The difference being that McCutchen has developed his power more fully, so when he makes contact (wherever that may be), he punishes it for more extra bases than Polanco heretofore.
Polanco is not going to have a BB rate of 23% and he’s not going to have a strikeout rate of just 13%. Pitchers will adjust and he will regress to the mean in both categories, but it’s not inconceivable to project him to have a walk rate of 12.5% and a strikeout rate of around 15-16% when the season is over. His adjustments seem to be real and well-defined.
Very enlightening. Thank you for this.