Seuly Matias is having one of the absolute craziest seasons I have ever seen from a professional baseball player. Major league, minor league, independent baseball, you name it. What he is doing in the South Atlantic League (A) has been absolutely bonkers to watch this season.

In 72 games with the Lexington Legends, Matias is slashing .215/.296/.562/.857 with a minor league leading 26 HR. He’s posted a wRC+ of 136, an unprecedented .346 ISO, a BB% of 7.2%, and a K% of 37.1%. 23.4% of the time that Seuly Matias swings at a baseball, he misses. In 8.9% of his plate appearances, he hits a home run. Seuly Matias has been a “three true outcome” king in 2018, but his power has been a ridiculously bright ray of sunshine for an underwhelming Royals farm system.

In a similar fashion, MJ Melendez is having a bit of an interesting season as well. He’s not been quite as powerful as Matias, but he hasn’t been completely hit-or-miss either. In 68 games this season, MJ Melendez is slashing .243/.303/.498/.801 with 13 HR, 15 doubles, and 6 triples. He’s posted a 121 wRC+, an impressive .255 ISO, a BB% of 7.7%, and a K% of 30.2%. His SwStr% is a much more reasonable 17.2%, and while MJ doesn’t quite possess the same power that Matias does, he’s doing this as a “defense first” catcher while being 19 years old in his first full season of professional baseball.

Both MJ Melendez and Seuly Matias have been ridiculously good in 2018. But they both have some interesting (and a bit worrisome) peripherals as well. Given the nature of how hard it is to play in full season ball as a teenager, I set out to see what I could find in the way of historic precedent. As a history teacher, this is exactly what I would want my students to do, so here’s my report on what I found.

There have been 55 teenagers since 2007 to post a 120 wRC+ in at least 250 PA in the South Atlantic League (A). Here is a bigger list of some names in that group:

• Seuly Matias
• MJ Melendez
• Khalil Lee
• Chase Vallot
• Victor Robles
• Brendan Rodgers
• Oneil Cruz
• Estevan Florial
• Calvin Mitchell
• Drew Waters
• Colton Welker
• Luis Alexander Basabe
• Luis Alejandro Basabe
• Ozzie Albies
• Austin Riley
• Rafael Devers
• Chance Sisco
• Ryan McMahon
• JP Crawford
• Nomar Mazara
• Manny Margot
• Joey Gallo
• Trevor Story
• Gary Sanchez (2x)
• Delino DeShields
• Bryce Harper
• Jurickson Profar
• Christian Yelich
• Xander Bogaerts
• Domingo Santana
• Nolan Arenado
• Anthony Rizzo
• Giancarlo Stanton
• Freddie Freeman
• Jason Heyward

There’s 36 of the 55 aforementioned players. 16/36 are still prospects, most of them are pretty highly touted or even top 100 guys. The other 20 are either very productive major leaguers or even All-Stars. 65.5% of those 55 players are either successful major league baseball players or are still prospects waiting for their chance. That’s a pretty dang good clip if you ask me.

Now, just because players posted a similar wRC+ at the same age doesn’t mean they’re all exactly the same, obviously. There are still 19 players on that list that haven’t had the MLB success that I think people would’ve hoped for (hello Jon Singleton). So, what separates the booms and the busts, and which do our Royals prospects most closely compare to?

One of the first things that I found to be a good predictor of future success is a player’s ISO. Seuly Matias is on pace to have the 2nd best ISO of our group of 55 (.346), while MJ Melendez is on pace to have the 4th best ISO of the group (.255). Here are some other names atop our list of 55 in ISO:

• Joey Gallo (1st, .365) – 106 wRC+ in MLB
• Giancarlo Stanton (3rd, .318) – 143 wRC+ in MLB
• Nick Williams (5th, .250) – 109 wRC+ in MLB
• Xander Bogaerts (6th, .249) – 104 wRC+ in MLB
• Bryce Harper (7th, .236) – 139 wRC+ in MLB
• Trevor Story (8th, .229) – 104 wRC+ in MLB
• 2011 Gary Sanchez (8th, .229) – 130 wRC+ in MLB
• Drew Waters (10th, .223) – Braves 2nd round pick in 2017, FanGraphs #94 overall prospect
• 2012 Gary Sanchez (11th, .221) – 130 wRC+ in MLB

The other two members of the top 10 ISO are Seuly Matias and MJ Melendez. Literally everyone else on this list is either an above average major league hitter for their career or a top 100 prospect (Waters). The average major league wRC+ of that group is 119. 119. And our boys Seuly Matias and MJ Melendez are out in front of almost all of ’em (Chase Vallot came in at 17 on the list, Khalil Lee at 28, 8 spots above Christian Yelich).

It is fair to still be cautious about our Royals prospects that are in this group. Seuly Matias is still striking out at a wild rate, after all, and his 23.4% SwStr% is a little bit scary as well. I have good news, however. Here is a list of players from our group of 55 to post a higher SwStr% than Seuly Matias in their time in the SALLY:

• Joey Gallo
• Domingo Santana
• Xander Bogaerts
• Nick Williams
• Giancarlo Stanton
• Gary Sanchez
• Anthony Rizzo
• Christian Yelich
• Trevor Story
• Delino DeShields
• Bryce Harper
• Nolan Arenado

All of those guys posted a higher swing-and-miss percentage than Seuly Matias as teenagers in the SALLY. Seuly still swing too often, and we’d obviously like to see him make more contact, but it’s not like what he’s doing is unprecedented. Seuly does strike out more than any other player on this list, but part of that can be attributed to Matias’ willingness to work the count as well. After all, we just saw that Matias doesn’t have contact issues as bad as some aforementioned All-Stars, so it’s fair to see he’s got time to work on his K%.

I’m not here to tell you that Seuly Matias and MJ Melendez are sure-fire MLB All-Stars. They both have still have serious kinks in their game that they will need to work out as they continue to advance through the ranks.

What I am here to tell you is that there is historic precedent for how good both of these guys have been, and the track record is reallllllllly good. Are there some misses on this list? Absolutely. Are there more hits than misses to this point? Oh yeah. Especially when you break it down from a power perspective.

Not that you needed me to tell you this, but you’re going to want to watch Seuly Matias and MJ Melendez as they grow up. These cats are going to be really special if history has anything to say about it.