Gregory Polanco Has Shortened Up

Event

Gregory Polanco has been an absolutely fantastic baseball player, having started to turn potential into results at the plate.

Explanation

Polanco has committed himself to various swing adjustments, as expertly documented by expert Travis Sawchik.

Further, unnecessary evidence for the explanation

Below!

Polanco is not someone who came out of nowhere. He was a big deal as a prospect, and because of that, people have been waiting on him to deliver, sometimes impatiently. It’s not our fault — it’s how we’re wired. As a young player, Polanco drew attention for what many considered to be a beautiful swing. And just based on its baseball aesthetics, yeah, Polanco’s swing could be gorgeous. But you know all about form vs. function. Beautiful swings aren’t always the most effective swings. Sometimes beauty can be downright useless! Polanco’s swing came with a pleasing, I don’t know, swoosh, but that same swoosh made him vulnerable. The Pirates wanted Polanco to tighten things up. Go read that Sawchik article, for more on the process. Polanco’s swing is no longer so loopy. A loop can be pretty, but it’s not a good way to turn on a fastball.

How about some images now? I got tired of looking for good, comparable video, so I’ve settled for screenshots. Below, two pairs, showing a home run from 2015 and a home run from 2016. The pitches are similar enough. The image on top is from last year, while the image on the bottom is from this year. Here are two shots of Polanco at contact:

These are both from a straight-on angle. Up top, Polanco is opening up. He doesn’t have his arms completely extended, but he’s getting there, and his left hand is well below his belt. Again, these are home runs, so it’s not like Polanco did anything wrong. Down below, you see that Polanco’s hips are more closed. And he has his elbows almost tucked in, with his hands close to the body. The bottom pitch is indeed a little higher than the upper pitch, but that doesn’t totally explain the difference. Here the left hand is closer to the belt.

Now Polanco just after contact:

I chose the moments when Polanco is pointing the bat toward the camera. Up top, Polanco is starting his follow-through, but his hands are still low by the belt, and the bat is angled down. You get a good sense here of the length of his swing, and this isn’t even one of the loopiest ones. Polanco drives through the ball horizontally. In the more recent image, the bat is pointed almost directly at the camera, instead of down. Polanco’s hands are above his belt, as he’s driving up through the ball. Both of these swings resulted in flies, but the bottom was more of a fly-ball swing. And it was most definitely the shorter swing. Look at how much more bent Polanco’s elbows appear. That’s how you keep your hands close to your body.

A sample of two swings is just that — a sample of two swings — but I do think this captures what’s been going on. Polanco’s swing has been a work in progress for a while, with a pretty consistent intent, and now it seems the instruction is setting in. Polanco has shortened up more consistently, and these days you seldom see one of the old, loopier swings. He’s gone through his phases, but this stretch is encouraging.

Here are some swing-rate heat maps, comparing 2015 on the left to 2016 on the right. These are from the catcher’s perspective.

What you see — what I see — is an uptick against pitches inside. At least, pitches low and inside, and pitches thigh-high and inside. Polanco hasn’t swung very much high and tight, but no one in baseball can damage those pitches. Taken on their own, I don’t know how much one would read into these maps, but when you consider the swing adjustments, this makes it look like Polanco feels more confident against pitches in. Because his swing is quicker, he’s more able to get to these pitches, so he’s more able to drive them. It’s not our only evidence.

According to Baseball Savant, Polanco’s average batted-ball speed hasn’t changed very much. However, against pitches over the middle of the plate or inside, Polanco is up an average of five miles per hour. Last year, among lefties, he ranked 66th out of 138. If he had this year’s average last year, he would’ve ranked seventh. That’s a pretty big leap. Additionally, last year, Polanco ranked in the 54th percentile in average batted-ball speed on flies or liners. This year, he ranks in the 88th percentile. So while Polanco’s overall average hasn’t budged much, he’s hit air balls with more authority, which explains why his hard-hit rate has gone up, and his soft-hit rate has gone down.

One more thing. As a rookie, Polanco was below average against fastballs. As a sophomore, he was again below average against fastballs. This year, his run value against fastballs is among the league leaders. It supports the idea of a quicker swing, and of greater bat control. All these pieces of evidence mostly point in one direction. Polanco has tightened his swing up, allowing him to do more damage against fastballs and other pitches in. That might conceivably cost him a little power the other way, but he’ll settle for the opposite-field line drives.

There’s one more benefit of the adjustments Polanco has folded in. A quicker swing gives him an extra split-second to commit. He’s also worked to keep his head more level, so it’s easier for him to track the path of the ball. That can lead to improvements in discipline, and we see now that Polanco has more walks than strikeouts. There are complicating matters: Polanco has one of the league’s lowest first-pitch-strike rates, and he also has one of the league’s lowest zone rates, so of course he’s walking — he’s not seeing many strikes. More strikes, at some point, will come. But Polanco does seem better equipped to identify and isolate them. He’s got some of the quickest hands in the game, and now he has a swing to go with them.

This feels like a big step forward. This feels like Polanco closing up a hole. Pitchers now might opt to go back to busting him outside. If the pitches in don’t work, there’s little sense in throwing them. But he has such a good line-drive swing now I don’t know what the best strategy would be. I guess high and tight, but that’s the strategy against almost everyone. Keep your eye on Polanco and see if he sticks with the swing that he’s got. Sometimes, players regress — muscle memory is a powerful thing. Polanco’s trying to rewrite that memory, and for every additional day, it’s a step toward the ultimate goal.