Ronald Acuna Jr has taken the 2018 MLB season by storm. He’s a 20 year old rookie, has played in 100 games, and has 26 bombs while being tied with Aaron Judge in offensive WAR at 3.8. Guys that are his age aren’t supposed to be that good. As a result of his offensive success, his swing has gotten a lot of scrutiny, both good and bad. In this article, I want to take a closer look at what he does and why his swing works for him, but might not work for others.
Let’s dig in. Here are a couple different views of Acuna, both side and front:
(clips courtesy of Craig Hyatt via Twitter)
A couple things you’ll probably notice/already know:
-He arm bars
-He has insane batspeed
-He doesn’t get very “deep”
The first two are pretty self explanatory, but I want to expand a little bit on the third. If you look at the video from the front view, you’ll notice you never see his rear elbow, or hands, on the posterior side of his body. He keeps them anteriorly, or more on the chest side of his body. What does that do? Take a look at these two slow motion swings from yours truly:
In which video do I have more time/distance to accelerate over? In which does the barrel cover more distance? It might be easy to say they cover the same, however you have to take the depth into account. In the second swing, my barrel gets further behind me, to the posterior side of my body, which means it has more distance to cover before contact.
The fact that Acuna gets less “depth”, or in other words, doesn’t get his elbow on the posterior (backside) of his body, means he actually gives himself LESS time to accelerate. All things equal, that should mean he has less batspeed than the average baseball player. Think about it like this: are you able to achieve a greater topspeed running for 10 yards or 30 yards? 30. The more time you have to accelerate, the faster you’ll be. So how is he able to create so much batspeed in such a short amount of time?
Before getting to that, I’d like to take a look at a second player, Khris Davis. A couple videos:
(video credit again to Craig Hyatt)
So we see almost the exact opposite with Davis as we saw with Acuna. We can easily see Davis’ rear elbow back behind his body as he loads, and we even get a glimpse of his hand. In addition, the direction of his lead leg as he strides is towards the shortstop. Here’s a quick experiment for you: stand up with your feet shoulder width apart. Position your hands at your armpit as Davis does. Now, simultaneously stride forward and pull your rear elbow back behind you. So you should land with your front leg in line with your rear leg and your elbow maximally pulled back as if you were doing a row. Reset. This time, instead of striding straight forward, stride towards shortstop, as if you were “stepping in the bucket” like we see Davis do above. Now what do you feel?
Most people won’t be able to get as much range posteriorly with their elbow when they step in the bucket. They simply aren’t mobile enough to do so. They hit max stretch sometime before that. So going back to the Davis versus Acuna example, we are seeing two guys moving completely differently, but producing similarly effective results (it’s pretty impossible to compare their results directly due to age and experience differences, but both are producing at the big league level).
What’s it mean?
Acuna and Davis have different body types. They have different abilities. Therefore, they are going to swing differently. So for players who are looking to maximize their own abilities, as Davis and Acuna have done (or at least gotten close to), they’re going to have to figure out what their own abilities are.
Here’s a quick and dirty test you can do to figure out what type of movement works best in your swing. You’re going to need a bat, a ball, a tee, and a way to track batted ball success (radar gun, open field, rapsodo, hittrax, etc). You’re going to go through three different swing variations. We’ll call them the Stanton, the Khris Davis, and “The Normal” (original, I know).
The Stanton:
Pretty simple: You’re going to try swinging like Stanton. Set-up closed off, front leg in front of the back leg, almost as if right field was centerfield, just like this:
Swing while maintaining this foot positioning.
Next…
The Khris Davis (“The Davis” didn’t quite have that ring to it)
You’re going to start with your feet in line, shoulder width apart. From here, as you stride forward, you’re going to step towards the shortstop. I know, I’m telling you to step in the bucket. Gasp. We’re experimenting, calm down. When you land it should look like this:
The Normal (There’s that ring)
I’m not going to post a picture of this one. You’re attempting to stride out straight and land with your feet in line.
Application
So, you’ve tried all three, what do they mean? Well, you may find that you’re unable to do one, or two, of the above. You may find that you THOUGHT you were striding open, but you were really striding straight. Or that you THOUGHT you were closed, but you really weren’t. If this is the case, don’t ditch them right away. Give it a week. Let yourself get comfortable with swinging in different patterns. If, after a week it still feels terrible and the results are bad, stop. You’ve now found what works for you. Use that.
And it might not be exactly like Stanton, or Davis, or “normal”. It may be somewhere in between. There are a lot of guys who swing closed off, just to a lesser degree than Stanton. And likewise, Davis is on the extreme end of stepping in the bucket. You don’t have to be extreme. But by going to the extremes, you’ll be able to feel them out, and find out what works for you.
Wrap Up
Going back to Acuna and Davis: they have found the specific swing characteristics that work for them. Whether that was through experimentation, or coaching, or luck of the draw happened to fall into it, doesn’t matter. There could be a number of reasons Acuna is able to accelerate so quickly over such a small distance. Maybe it’s cause he’s practiced like that for so long. Maybe it’s cause he’s at optimal length/stretch there. Maybe he’s just a freak. Who knows. But that’s beside the point. Go out and test for yourself. Don’t blindly swing like Davis, or swing like Acuna, or anyone else. Test different swing characteristics, in a measurable manner, and figure out what works best for you.
That’s all I got for today. Hope it helped.
Questions, comments, or interested in remote training with DAC? I can be reached via email at brady@dacbaseball.com.