One of the best stories in baseball in 2024 was Jackson Merrill, who became the youngest Opening Day starting centerfielder since Ken Griffey Jr. All he did after that was bat .292 and hit 24 home runs on the way to one of the better rookie seasons we’ve seen in recent memory from a hitter. If not for Paul Skenes being… well… Paul Skenes, Merrill would have been the unanimous NL Rookie of the Year. He even managed to take seven 1st place votes away from Skenes.
Part of the surprise in his rookie breakout was that Merrill was not considered by many prospectors to be an elite prospect. Sure he was a 1st round pick, but you would have had to search far and wide to find an outlet that had him ranked as a top 10 prospect prior to his debut. I personally had him 16th, which I felt at the time was aggressive. The main reason, in my opinion, that he didn’t get more love was because of his power projections. The hit tool was thought to be very advanced, but most places had him projected for average game power. He hit 15 home runs in 511 PA between A+ and AA in 2023, and hit only 6 the year before that. Then, to most people’s surprise, he clubbed 24 as a rookie while playing half of his games at Petco Park, which has the third worst Park Factor for left-hand hitters per Baseball Savant. While I’m sure he got physically stronger, there had to have been something in his batted ball data in the minors that suggested this power increase was coming. More importantly, if we can figure out what it is, maybe we can find the “next” Jackson Merrill.
Luckily, for the sake of my comparisons, Jackson Merrill has a great minor league hitting sample to pull from. I tend to use 200+ plate appearances as my marker for minor league hitting data. Between 2022 and 2023, Merrill got 200+ PA at three different levels (A, A+, AA). Which means maybe we could find more than one Jackson Merrill! For this article, however, I’m going to focus mostly on Single-A and High-A. These are my ideal buying levels. By the time guys have played a full season of Double-A, the window I like to buy in is almost closed. Don’t worry though, there might be a bonus player or two from this level at the end.
When I jumped into Jackson Merrill’s minor league data, I saw tons of similarities with what I found in my Kristian Campbell deep dive. Which makes sense. Not only are they great contact hitters, but they’re incredible line drive hitters. When you’re that advanced of a hitter, who is already hitting hard line drives and moving the ball easily to all fields, the “random” increases in home run output maybe aren’t that random. Let’s take a look at some of Merrill’s minor league advanced stats.
If I had to nail down some metrics that I think could have predicted Merrill’s power increase, the first three in that table would be my first choices, and they were pretty identical. While he wasn’t hitting a ton of homers, he was hitting the ball hard consistently, with ISO’s over .150 at both levels. Let’s start there. If we set the same age parameters, 19 for Single-A and 20 for High-A, and filter it by prospects with 200+ PA and an ISO over .150 we get:
Twenty-two players for Single-A and nineteen for High-A.
If he was hitting the ball hard and for extra bases, why wasn’t he hitting more home runs? Well, because he didn’t hit the ball in the air. Although the home run numbers didn’t pop, the good HR/FB rate suggested that he could go deep when he actually hit the ball in the air, something he did more frequently in the MLB. In order to find prospects with a similar hitting style whose power may not have flashed yet, I’m going to narrow it down to guys with a similarly low fly ball rate but equally good HR/FB. If you take the list of names above and remove anybody with a fly ball rate over 35% and HR/FB under 10% it leaves only:
Four prospects for Single-A and four for High-A.
Now we’ve got a list of guys who like Merrill, are hitting for extra bases (ISO), but aren’t hitting the ball in the air much (FB%). However, when they do get some air under it, they don’t have a problem getting it over the fence (HR/FB). Since that is narrowed down, the next step is the easiest. You can’t be Jackson Merrill without excelling at making contact, his strongest tool. That’s why I added his SwStr% numbers in the table, because they’re fantastic. The question is how many current prospects share that similar ability? I can tell you this, if you take our lists of four Single-A and four High-A hitters and knock off anyone with a SwStr% over 8% it leaves us with…
One of each.
Single-A
J. Merrill (2022) - .157 ISO, 25.7% FB%, 12.8% HR/FB, 7.4% SwStr%
Player A (2024) - .203 ISO, 34.1% FB%, 19.1% HR/FB, 7.5% SwStr%
Can’t lie, that’s a silly stat line. For any 19-year-old to be making contact that frequently, with an ISO and HR/FB rate that high is no joke. The fly balls are more frequent but the stat line itself is actually more impressive than Merrill’s. Who does it belong to?
Zyhir Hope of the Los Angeles Dodgers. Not a ton of surprise for me, as I ranked Hope 11th on my list of non-debuted hitting prospects the other day. Offensive potential here is special. I’m sure some of you read the name and sighed in disappointment, and for those who didn’t, I’ll explain. Hope has a very unique and unfortunate Bowman circumstance. He was supposed to get a 1st auto in 2024 Chrome, but to my knowledge less than five of them have ever publicly surfaced. Then there was a moment of excitement when he was put on the 2024 Draft checklist for getting his first non-auto, but to the dismay of many that card wasn’t given a 1st stamp. While it makes collecting him extremely difficult, I do think ultimately the colors and parallels of his 2024 Draft card will sell well as he gains popularity, despite not being a “true 1st”.
High-A
J. Merrill (2023) - .165 ISO, 32.9% FB%, 12.5% HR/FB, 7.1% SwStr%
Player B (2024) - .175 ISO, 31.8% FB%, 11.3% HR/FB, 7.4% SwStr%
This one is a pretty good copy. Slightly less of his fly balls go deep (1.2%), and he hits less fly balls in general (1.1%), but we’re splitting hairs at that point. Almost equally as good ability to make contact, and actually hitting for more raw power. Those who have been following me for awhile are going to love who this one is…
That’s right, Sal Stewart of the Cincinnati Reds. He was the runner-up comp in my Kristian Campbell article, and now he’s the closest High-A comp to Jackson Merrill. Not bad hitting company to be in. I’ve already written up the Reds team buy sheet and Stewart was a 5, I actually said if I could give him a 6, I would. He is arguably the most undervalued hitting prospect in the minors right now for me. Every single hitting metric is impressive. He is one of the best line drive hitters you’ll find at his age and playing level. Stewart rarely swings and misses, his raw power has been great, and he has the frame and skills to turn it into more game power. It’s not a mistake that using entirely different hitting statistics he hung around as such a close comp to both Campbell and Merrill when trying to predict the next breakout prospect. I’ve been conducting the Sal Stewart hype train for a bit, no reason to stop now.
Player C
Bonus round right here because this player hung around much longer than expected when I was filtering out stats and I think he deserves a shoutout because his cards aren’t very expensive.
2024 (A+) - .169 ISO, 36.8% FB%, 14.3% HR/FB, 6.4% SwStr%
He was knocked off for barely crossing the fly ball rate threshold, but his HR/FB and his SwStr% are actually better than Sal Stewart and Jackson Merrill for the level. Ready for your mind to be blown? That’s Milwaukee Brewers prospect Luke Adams. This stat line is surprising because Adams stands 6’4” 210 pounds, built similarly to Coby Mayo, and starts his swings with an almost comically large leg kick. He batted just .227 last year but still posted a 154 wRC+ thanks in part to a 18.7% walk rate and .443 OBP. You’d never guess by looking at him, or watching him swing, that he posted an almost 80% contact rate last year, while swinging and missing less than 7% of the time. It’s a strange profile but put a pin in Luke Adams and see how he starts the season in 2025. His giant frame and plus power potential is extremely intriguing for a guy making that good of contact.
Players D & E
I promised earlier that despite it not being my buying zone, I’d give you a Double-A comp for Jackson Merrill. Now Merrill’s AA metrics weren’t identical to his A and A+ ones, but for fun I applied those ones to all 20-year-olds who got 200+ PA in Double-A last year and these were the two closest comps:
Player D (AA) - .220 ISO, 34.7% FB%, 19.2% HR/FB, 8.9% SwStr%
Player E (AA) - .196 ISO, 36.4% FB%, 15.0% HR/FB, 8.5% SwStr%
You won’t be surprised to learn that Player D is none other than #1 prospect Roman Anthony. Plays a similar game as Merrill but has already shown more power, making him deserving of his rank as the best prospect in baseball. If you want someone who might not look the same as those two, but whose offensive production has suggested he’s capable of hitting the same way, Player E is Moises Ballesteros of the Chicago Cubs. If you’re looking for some under the radar value, his autograph prices are much more palatable.