How Ronald Acuna Jr.'s strikeout rate has been key so far to his monster 2023 season
Even by his lofty standards, what Ronald Acuna Jr. is doing with the Atlanta Braves has been absolutely ludicrous. Through 43 games (197 plate appearances), he is slashing .345/.437/.613 with 11 home runs and 18 stolen bases. He leads the league in fWAR at 2.4 and is second to Yandy Diaz in wRC+ at 181. Right now, he is the runaway favorite in the National League MVP race with the usual "there is still a lot of season to go" caveats.
To be clear, he has always been talented enough to do this. His combination of tools and energy seldom comes around, so when he is on...he is the best player in the league. The biggest thing the last couple of years has been his health and now that he seems to be fully healed up, he is making up for lost time.
While his health is the biggest reason for him going Super Saiyan this year, there is another key component to what he has done and that is his strikeout rate has plummeted this season. Here is a look at what has changed there so far.
Ronald had always struck out a fair bit in his career
It isn't a secret that RAJ goes up to the plate looking to do damage and has been that way since he entered the league. With that approach is going to come some strikeouts and Ronnie did strike out a good bit. Through his first five seasons in the league, Ronald struck out at around a 24-25% clip. Not terrible especially since he got his fair share of walks, too, but not great, either.
While there was a bit of a spike in his strikeout rate in 2020 where it approached 30%, his strikeout rate was pretty consistent and many of us assumed that that was just who he was as a hitter and that was perfectly fine with us.
The 2023 season, at least so far, has been a different story.
2023 has seen Ronald Acuna Jr.'s strikeout rate plummet
It is still early and things may start approaching his career norms as the season goes on, but one thing that has gone under-appreciated this season is just how much Ronald has cut down on this strikeouts. Remember those 25%-ish percent strikeout rates earlier in his career. Yeah, he is down to striking out at just 13.2% of the time. That is a big difference, so what changed?
The obvious thing to point to is the health thing again. Ronnie was getting beat a good bit last year on fastballs 1) because he was rusty from all the downtime and 2) because his back leg wasn't fully healthy yet thereby impacting his swing.
A deeper look at his Statcast profile (which everyone should look at because it is beautiful) actually gives us some really interesting information here. Ronnie's whiff rates on all types of pitches (fastballs, breaking balls, and offspeed stuff) have all historically been mostly between 20% and 30% in his career with breaking balls being a touch better than that over the years.
On fastballs specifically, we are talking about whiff rates more in the range of 23-26% from 2018-2022. This makes some sense in how we remember teams pitching to Ronald as one of the ways to beat him was velocity in on his hands (or in the case of the Marlins under Don Mattingly, fastballs at his body on the regular).
How does that compare to 2023? Well, instead of a whiff rate of 23-26% on heaters, Ronald is only whiffing 13.7% on the hard stuff. While it looks like he can still get beat on offspeed stuff this year, if he swings at a fastball, he isn't missing it. When you factor that along with the fact that he is hitting the ball harder than he ever has (95 mph average exit velocity is a career high) and is hitting the ball hard very, very often (54.6% hard hit percentage is just nutty), well...you are seeing what happens.