Paul Goldschmidt has a Groundball Problem

The Cardinals dealt for slugger Paul Goldschmidt this past off-season and the praise was universal. They finally found a star hitter who could help the lineup reach previously untapped potential while also benefitting the infield defense. Goldschmidt did his part to stoke excitement by blasting three homeruns in the second game of the season and earned a massive ovation in the home opener when he hit an eighth inning homerun. He ended his first April as a Cardinal with a solid 125 wRC+ with hope for more. Since May 1st (through Tuesday night), he has a meager 89 wRC+.

His batting average (.259 before, .252 after) and OBP (.348 vs. .341) are unchanged. His walk rate has held steady, his strikeout rate has decreased, and his BABIP has even increased from .288 before May 1st to .318 since. For good measure, his line drive percentage has gone from 15.9% before to 25.4% after. Still, his overall production has collapsed. His power has evaporated. His ISO has gone from .259 before to a Kozmaesque .097 since.

Early in this stretch on May 3rd, he went 0-for-4 against Kyle Hendricks. There were two groundball outs buried in his four hitless appearances. Those groundballs were a harbinger of things to come. His 37.8% groundball percentage and 0.82 GB/FB through April 30 have mushroomed to 44.7% and 1.5 since. They answer most of the question of where Goldschmidt’s power is hiding. His true popup percentage has also increased 3.2%- about five more popups over his pre-May 1st rate. However, I’m going to focus on the groundballs today.

First, let’s zero in on the fact that he’s hitting more line drives. That indicates that he’s still hitting the ball with plenty of authority. I’m a big fan of Zach Gifford’s 95 mph exit velocity line of demarcation (in case you can’t tell by the three or four times I’ve linked back to it). With that as our divider, we can use Baseball Savant to see if it has changed. As a matter of fact, it has changed... but in a positive way. Before May 1st, 39.02% of his batted ball events were 95+ mph exit velocity. Since then, it’s 41.96%.

Sticking with Baseball Savant, here are spray charts of Goldschmidt’s batted balls at 95+ mph exit velocity. With apologies to Baseball Savant, I’ve made some very light adjustments- primarily changing the dots marked “single” to black in the interest of visual contrast between them and force outs (and double plays).

These graphs make it very simple. You’re looking for pink, blue, and lavender dots, particularly on the infield- the groundball outs. There’s clearly a significant increase as the season has progressed. Similar to Marcell Ozuna early last season, Paul Goldschmidt is giving a lot of headaches to a lot of worms.

Pitch Types Causing the Groundball Spike

We can look at which pitch types he’s hitting 95+ mph, before and after, to get a feel for what he’s seeing more frequently since May 1st. This table gets us started:

The largest increase happens on changeups, followed by sinkers and two-seamers. There’s also a small increase in curveballs, but it amounts to a single pitch. It’s mostly happening on soft stuff- changeups, softer breaking balls, and fastballs other than four-seamers. However, this table only shows where he’s hitting more hard contact. It doesn’t show where he’s hitting more groundballs on hard contact.

He only had seven groundballs of 95+ mph exit velocity before May 1st, so there’s not much of a sample to compare against our post-May 1st group. Instead, let’s look at the percentage of his 95+ mph exit velocity events going for groundballs, by pitch type:

The cutter and curve situation involves a single event, which is meaningless. The biggest bumps to his groundball percentage, in any significant volume, are happening on change-ups and sliders. He’s hitting them hard, but right into the ground. This dovetails nicely with the previous table, which illustrates that a lot of his hard contact is happening against those two pitches. The difference is that the sliders are frequently going for hits (three of the five 95+ mph groundballs were singles), whereas the change-ups have all been outs. On change-ups, it’s especially happening away in the zone.

Here’s how it looks:

Note: I wrote this Wednesday afternoon. That night, Goldschmidt drove this exact same pitch, from Conley, 454 feet for a walkoff homerun.

Goldschmidt’s overall production against hard stuff- four-seamers and sliders- remains above average. He has a wOBA of .397 against those pitches this year, compared to .332 league-wide. If you limit it to just sliders, he’s at .331 compared to .279 for the league. That’s upper-quartile production and nearly identical to his 2018 production against those pitches. He also does well against all other fastballs (cutters, two-seamers, and sinkers), with a .359 wOBA compared to a .345 league average. He did more damage against those pitches last year, but he’s still above average so far this year.

Change-ups, on the other hand, are less kind. He has a .131 wOBA and .247 xwOBA against them this year compared to league-wide averages of .286 and .290. His production on curveballs is right in line with the rest of the league (.279 vs. .278), but the problem is that it’s a significant decrease from .406 last season. That said, we’ve already seen that curveballs aren’t the source for the increase in groundballs. It’s mostly a change-up problem.

Conclusions

Goldschmidt may be sitting dead red more often to combat any age-related decline or simply the fact that there are more pitchers with face-melting queso in the league than ever before, even if fastballs are being thrown less frequently. It’s hard not to wonder if that’s the case given his age and the hullabaloo about his struggles with higher velocity early last year. That would be one explanation for how he’s maintained production on the hard stuff while slipping a bit on change-ups and curveballs. He certainly wouldn’t be the first, nor will he be the last, hitter to make a subtle adjustment like that as they age. It’s obviously speculative on my part to arrive at that conclusion- there’s no way we could ever know.

Regardless of whether or not that’s the case, it seems Goldschmidt would benefit from letting more change-ups and curveballs go until he reaches a two strike count. Why swing at a pitch where you do less damage? That’s the approach he took against Conley Wednesday night. He took one change-up for a strike, another for a ball, fouled off the third with a two-strike count, and parked the fourth one close to Big Mac Land. Of four change-ups, he swung at two and both were with a two-strike count.

Granted, that’s easier said than done, particularly since the whole point of a change-up is to disrupt timing with deception and lack of velocity. It’s made to look like a fastball as much as possible in hopes of forcing a hitter into weak contact. Still, a more selective approach would appear to be the easiest solution for Goldschmidt’s groundball woes.