Exploring Ronald Acuña Jr.’s offensive dropoff in 2022

Ronald Acuña Jr. made his much-anticipated return from injury for the Atlanta Braves on April 28. Most people figured it would take him a while to get into a groove after missing a large chunk of the 2021 season, and then Spring Training as well. And, it did take him arguably about seven or so games to get going. Up until May 7, Acuña was hitting .207/.281/.345.

Of course, seven games is a small sample size, and anything can happen in seven games, returning from injury or not. But, those seven games did little to refute the idea that his injury would play a role for him this season , and it seemed to right from the start.

It also looks like it continued to play a role throughout the season, beyond those seven games, in most facets of the game. His offense dropped to a wRC+ of 114 (14 percent above league average), which is well below his career mark of 134.

His one defensive run saved (DRS) in 793 innings in the outfield, and -6 outs above average (214^th in MLB), were both career lows for him as well.

This is not to say that Acuña had a “bad year,” per se, especially compared to mere mortal baseball players. His 2022 was just much lower than we are used to seeing from him. With an fWAR of 2.2, this tied him for 83^rd in MLB. A 2.5/600 mark is plenty fine for most players, if horribly underwhelming for a guy like Acuña.

In addition to coming off major injury, though, Acuña’s mediocre performance had another legitimate excuse: his Statcast metrics still looked solid in many areas, meaning that plain ol’ bad luck was at least part of the story of his season. His xwOBA was in the top five percent in MLB and the associated expected stats (xSTATS) that go along with it were well above average as well (xBA, xSLG, etc.). Among players with 340+ PAs, only 13 underhit their xwOBA more than Acuña. If you relax the cutoff to 200 PAs, he still lands in the bottom 20. Only ten players had more homers “lost” due to park dimensions. All of his 15 homers would’ve been gone at 29, or usually, all 30 parks. On the three balls he hit that would’ve been out at 22 or more parks, none went for homers, and one was an out. On fly balls in general, he had an xwOBA .223 greater than league average... and a wOBA just .055 higher than league average

Even though his Statcast offensive numbers look more than solid, let’s explore what else happened at the plate that resulted in his wRC+ being 20 points lower than his career average.

What changed at the plate for Ronald Acuña?

If we look at some of the areas that one might look at first while investigating an offensive drop-off, there are not many red flags. His swing and miss percentage in and out of the strike zone, and his chase rate were either better than his norm, or right on par with what we are used to seeing. In other words, it is not like he started missing more pitches while swinging.

In fact, his strikeout rate was the second lowest of his career at 23.8 percent, while swinging at the first pitch a career high 38.1 percent of the time (3.1 percent higher than his career average).

So, if it is not swinging and missing more often, then what could be what caused the drop-off?

First, Acuña’s average exit velocity (EV) was the second lowest of his career against fastballs and breaking balls. As can be seen in the chart below, his EV against fastballs (91.4 MPH) was only lower in 2019, when it was 90.1 MPH.

Against breaking balls, Acuña’s 89.4 MPH EV was only lower way back in his rookie year when he had an 88.8 MPH EV against them.

To be fair, he did rank 33^rd in all of MLB in average EV, but it wasn’t quite the ringing contact we’ve come to expect from the kid.

Acuña’s EV drop intermeshes with an overall diminishing of his quality of contact. His weak hit percentage of 5.8 percent was the second lowest of his career (career average: 4.7 percent). His solid contact rate in 2022 of 6.1 percent is also well below his career rate of 8.4 percent, and the lowest of his career in any season. His barrel rate of 12.8 percent was also the lowest of his career (his career average is 15.0 percent).

It should be noted, that this is Ronald Acuña Jr. we are talking about. A superstar talent. Even on his “down year” he is better than most players. Just for reference, we mentioned that his barrel rate (12.8 percent) and solid contact (6.1 percent) were the lowest of his career. However, these rates are still higher than the MLB average for Acuña’s entire five-year career span.

During these five years, the MLB average barrel rate was 6.7 percent, and the league average solid contact rate was 5.7 percent. So, it is not like Acuña has been bad in these areas, it is just a factor in why his output was not at the regular “Acuña level” in 2022.

Perhaps the biggest non-luck area that played a role in Acuña dropping off in 2022 is his grounder rate. His 47.7 percent rate of hitting grounders was by far the highest of his career, and well above his career average of 40.6 percent. Just for a reference point, the league average ground ball rate in 2022 was 43.6 percent. This shows that even with a shift in overall offensive output across the league, Acuña still struggled in the arena of getting the ball off the ground.

Even worse, these were not always well-hit grounders. “Topped” balls are routine grounders that are almost always outs: his topped percentage was by far the highest of his career at 32.3 percent. His next-highest topped rate was way back in 2018 at 29.4 percent. His career average topped rate sits at 27.1 percent. If you look at his overall quality of contact, he essentially traded six well-hit balls out of every 100 for do-nothing grounders or tappers, which is a pretty big deal given that even elite bats only manage to do something interesting with a ball in play around 45 percent of the time.

One possible cause for the diminished contact quality? Well, it’s pretty easy: he swung a lot more. His swing rate was 47.9 percent, a career high. He swung more than ever at strikes, and hit strikes more than ever. He chased more than ever (albeit mostly on pair with 2018-2019, and still way below the MLB average chase rate), and made more contact when chasing than any of his seasons save 2020, which was barely higher. While his overall approach was still broadly in line with the Braves’ batting philosophy of “only swing on things you can damage, and make your swinging a damaging one,” especially when compared to other batters, he was expressing that philosophy way less than before, and making a bunch of outs early in the count by swinging and hitting grounders rather than both waiting for his pitch, and putting a more destructive swing on it, than before.

Summary

Acuña is a superstar level talent. Even coming off a major injury, and having a down year by his standards, he still produced a batting line that was 14 percent better than league average. Ultimately, it is a hitter’s job to create runs, and Acuña was doing it at an above-average rate in 2022.

With that being said, we did see a drop off in his production. We knew this was a good possibility, but we can also pinpoint what changed, other than just a blanket statement of “well, he was coming off injury with no Spring Training!”.

Ultimately what changed was pretty simple. The quality of his contact declined, both in terms of how much he hit the ball on the ground, and how hard he hit it. Some, or a lot, of that is related to him swinging, and hitting the ball more often, perhaps trading some power for contact for an unclear reason.

Swinging the bat more, and making more contact, is not always bad. However, if when you do hit the ball, you are not hitting it as well, an uptick in swings results in more poorly hit balls. More poorly hit balls equal a dropoff in production. This seems to be the cause of the Acuña’s dropoff.

Here’s to hoping Acuña can fully recover and return to his 2020-2021 production level. The way to do so from a swing decision standpoint seems pretty clear. But, even if he can’t quite get back there, he’s still a superstar-level talent that any team would be happy to have.