Why the Braves Couldn't Leave Briggs McKenzie in Augusta

Atlanta's newest pitching prospect wasn't promoted because of one dominant start. He was promoted because Low-A may not have had much left to teach him.

You’d be forgiven for not knowing that Atlanta’s first-round pick in last summer’s MLB Draft, shortstop Tate Southisene, wasn’t actually the one that got paid the biggest bonus by the Braves.

That’s usually how it works. The first-round pick gets the biggest bonus, carries the highest expectations, and becomes the face of the draft class.

And don’t get me wrong, Tate Southisene’s taken a leap in his first full season with Atlanta. He’s hitting .296/.429/.498 in his 54 games played, all but three of which came for Single-A Augusta. He has eight home runs and 37 stolen bases, putting up a 155 wRC+ that is the best mark of any player with one of Atlanta’s full-season affiliates.

But no, the biggest bonus actually went to 4th-round lefty Briggs McKenzie, who got paid $3M on a slot value of just $588,900. And all he’s done since getting started in full-season ball is force the Braves to push him up to High-A after one single start in Augusta.

Not as a reward, but because he needed to develop.

Let’s talk about it.

Why this promotion was different

When the Braves promoted MacKenzie to Rome, the reaction was predictable.

The 2025 fourth-round pick had struck out eight batters in five innings while allowing just one hit and one walk. The numbers were dominant, and the promotion felt like a reward.

But according to Braves prospect analyst Gaurav Vedak, the promotion had less to do with the box score and more to do with the type of pitcher MacKenzie already appears to be.

The Braves weren’t promoting him because he dominated Low-A hitters.

They were promoting him because Low-A hitters may not have been helping him develop anymore.

For most teenage pitching prospects, Low-A is where the real work on being a professional begins. Prep pitchers tend to spend most of, if not their entire, first season in the lowest level of the minors, learning to handle the physical demands, focusing on throwing the secondary pitches for strikes, and acclimating to professional hitters. Even the fast-moving ones typically aren’t exempt from this; AJ Smith-Shawver spent the entirety of his 2022 season in Augusta at age 19, making 17 starts and covering 68.2 innings, despite eventually reaching Atlanta less than a year later.

The reason is that most prep pitchers, on the field, are working on some things that aren’t a big part of the high school and showcase experience: getting comfortable with their secondary pitches and learning to land everything for strikes.

What makes McKenzie different

McKenzie throws the usual four-seam fastball, pairing it with a changeup and a curveball. He’s dabbled in a two-seamer, which is a development point we’ll get to in a future newsletter, but he’s able to throw all three of those pitches for strikes already.

And when it comes to his ability to spin a baseball, he’s pretty advanced. Not for his age, for baseball.

Per Gaurav, McKenzie’s curveball has been measured at around 3,100 RPM. That’s not exceptional for a teenager. That’s exceptional period.

Charlie Morton’s best Braves seasons featured a curveball spinning in the same neighborhood. Former Braves starter Max Fried has only crossed the 3,100 RPM threshold a handful of times this year with his renowned curveball.

The spin rate isn’t what got McKenzie promoted, though.

What got him promoted is that he can already pair that curveball with a quality changeup, throw both pitches for strikes, and maintain his fastball velocity throughout an outing.

The Braves aren’t dealing with a teenager who has one remarkable pitch. They’re dealing with a teenager who already looks comfortable pitching.

The Braves need better information

For as much work as prep pitchers are doing in that first year in Low-A to adjust to the professional game, the hitters are doing the same. These are some of the youngest prospects that are stateside in an organization, and there are a lot of areas of baseball where they’re exceptionally raw.

Low-A hitters chase more, especially against spin, which they recognize less often. And when they do get lucky and get a mistake pitch, they’re not always doing damage against it.

That makes evaluation harder.

So the Braves moved McKenzie up to Rome, because a curveball that gets six whiffs in Augusta might get taken for a ball in Rome.

That’s useful information.

A changeup that dominates inexperienced hitters might need refinement against more advanced hitters.

That’s useful information.

The promotion wasn’t a reward for a dominant debut: It was a test.

The Braves aren't trying to find out whether Briggs MacKenzie can dominate Low-A hitters. They already think he can. They're trying to find out what happens when he faces hitters who won't cooperate.

SIDEBAR: Know how sometimes it feels like Braves prospects don’t get the attention they deserve from national media and prospect rankings? This is why. If Briggs McKenzie were to stay in Augusta all season and dominate the Carolina League the same way he did Delmarva in that first start, he’d be a no-doubt top 100 prospect by the end of the season. But would he be a better pitcher? That’s very much in doubt.

Why this matters for the system

Atlanta’s always been aggressive with their top prospects, moving them rapidly through the organization until they find the true test of their talent level and current state of development. Sometimes that ends up being Atlanta. Sometimes it’s lower.

What they’re doing with Briggs McKenzie is no different than what they did with AJ Smith-Shawver, or Spencer Schwellenbach, or Didier Fuentes.

They’re trying to get information on where to go with the development next.

This isn’t a declaration that MacKenzie is a future ace. It’s a declaration that the organization believes he’s ready for a harder challenge.

That’s significant after one professional start.

Briggs MacKenzie still has plenty to prove: One start doesn’t make a prospect, and one promotion doesn’t guarantee future success. But the Braves’ decision tells us something important.

They aren’t treating McKenzie like a pitcher who needs to survive Low-A.

They’re treating him like a pitcher whose next developmental questions can only be answered somewhere else.

Most teenage pitchers spend Low-A trying to prove they belong.

Briggs McKenzie may have already forced the Braves to start looking for the next question.