Atlanta Braves: Why Ronald Acuna Jr. Ranks in Bottom 5% in Outs Above Average (OAA)
We explain why Ronald Acuna Jr. ranks as one of the worst outfielders in the MLB when it comes to range. How does the SB leader have no range? We explain.
Acuna Defense: How Outs Above Average (OAA) is Calculated
If you need a refresher on how OAA works, you can click here or accept my succinct run down in the next couple of sentences. Statcast measures the probability of a catch based on the distance the fielder needs to run to get to the ball and the hangtime of the ball. Based on those numbers, it calculates the probability of the average outfielder making the play. If a play is made by 99% of outfielders then there are two outcomes. One, the catch is made and the player receives the difference of the probability as a credit. 1-.99=.01.
You don't get a huge reward for making a play you are supposed to make in the big leagues. However, if you miss those routine plays, then you deserve a smack on the wrist. Missing the subtracts .99 from the player's score. That's detrimental to most defensive metrics. Players who lack range really stick out in OAA because when they miss a high-probability catch, they usually have a tough time making up for them with spectacular low-probability plays. In other words, it's all downhill from there.
Why is Acuna in the Bottom 5% in Outs Above Average!?
Thanks for listening. So, if a player like Kevin Kiermaier makes a mistake on a routine flyball, he's going to be fine because he gets tons of credit for making those highlight plays where he streaks through the outfield like a leather-seeking missile fired out of a fighter jet. On the other hand, if Marcell Ozuna misses a routine flyball... he's toast. He's not making that point up.
So, why is Acuna more like Ozuna rather than Kiermaier? Is something off here? Are we missing something? Go to the next slide to see what's actually going on. Videos are included on the next slide.
Ronald Acuna Jr. Defense - Video Evidence
Let me start by directing you to a really cool page. The fielding section of Ronald Acuna Jr.'s Baseball Savant player page. If you scroll down, you can see a chart showing the catch probability for Acuna's plays this season.
Now, I would like to direct your eyeballs to video evidence of plays Acuna didn't make that most major-league outfielders would have.
Exhibit A - Acuna Can't Make the Play on a High Fly with 99% Catch Probability
Exhibit A - The catch probability on (the video is in the "Exhibit A" link) Exhibit A is 99%. So watch the video and just know that based on the distance he needed to travel and the time the ball was in the air, 99% of major-league outfielders would have made this play.
You can see Acuna makes a bad read backward, then he freezes for an odd amount of time and then goes on a sprint toward the ball. Even the announcers were shocked. This is a good example because a lot of camera shots don't cut to the outfielder quickly enough to show the initial read.
Exhibit B - Acuna Pulls up on Flyball with 99% Catch Probability
Exhibit B - Here Acuna pulls up on a ball that most players would catch. I included this one because we have seen this a lot from Acuna this year. They aren't always on 95% catch probabilities, but this one is.
Exhibit C - Acuna Gives Jason Heyward a Hit by Pulling up on Flyball with 95% Catch Probability.
Exhibit C - Here is the ball he pulled up on against the Dodgers. Jason Heyward hit a "routine flyball" as the announcer said. Acuna pulled up and let it fall. This is a ball most major-league outfielders are going to catch. When I saw Acuna stop short on this ball on Sunday, it brought back memories of the research I had done. That ball should have been caught, especially with Acuna's speed.
3 Reasons Acuna Doesn't Have Range
The previous page only provided three examples. You can explore more at Acuna's Baseball Savant page. You can also see more video examples from earlier in the season embedded in this article about Acuna's defense. Acuna misses a lot of high-probability catches. He also doesn't make up for the point deductions by making the low-probability catches. He just doesn't have any range in the outfield.
When you start doing the math on that, it doesn't work out in Acuna's favor. The three videos I linked earlier in the article were worth about -3 OAA. Acuna's problem is he doesn't make up for those with any low-probability catches. He can't make a play that 99% of outfielders won't make so that number won't go back down to two.
He just doesn't have much range!
There are a couple of reasons he likely doesn't have the range you would assume the league's leading base stealer would have.
1. Reads
He doesn't make good reads. You can see it in the videos, especially when the camera catches him before he makes his break. Whether it is a high flyball or a line drive right at him (99% catch probability)... he's not seeing the balls well off the bat.
2. Play-it-Safe Routes
He takes a lot of play-it-safe routes. Many 50/50 type balls on the Savant page show Acuna conceding the hit and circling in to field it on the bounce. He doesn't really go for balls he isn't sure he can get.
3. Protecting the Knee
He might be protecting his surgically repaired knee. I don't think anybody is complaining about the notion that he is protecting himself. Between 2018 and 2021 he had +5 OAA. Since the beginning of 2022, he has -12 OAA.
Does This Mean Acuna is a BAD Defender?
If Acuna wants to play it safe on 50/50 balls then at least we don't have to worry about him diving and letting balls get by him. They don't have a negative metric for that, btw.
His lack of range doesn't make him a below-average outfielder. He makes up for it in other areas. In his career, he's been a +10 DRS right fielder and a +4 center fielder. This season, he has posted zero defensive runs saved in right field, which means he is average.
We love Acuna and he's still our MVP. This topic comes up a lot and the Heyward flyball seemed like another good opportunity to dive in. Sorry. Go Braves!