This week, the Red Sox informed prospect Kristian Campbell that he’d made their Opening Day roster. Campbell, a 22-year-old second baseman who was drafted in the fourth round in 2023, has 137 games of minor league experience. That makes him well seasoned compared to Cam Smith, a 22-year-old outfielder who made the Astros roster after Houston acquired him from the Cubs in December’s Kyle Tucker trade. Smith, who was drafted 14th last year, has 32 minor league games on his career résumé. Which makes him a veritable veteran compared to Ryan Johnson, a 22-year-old pitcher who crashed the Angels roster. Johnson, a second-round draftee in 2024, has yet to pitch in a professional game. He’s about to become the first player to bypass the bush leagues en route to the big leagues since Garrett Crochet in 2020—or, excluding 2020, when the minor league season was canceled, Mike Leake in 2010.
These early arrivals speak to a strange dichotomy in modern player evaluation. On the one hand, times are tough for old players. Studies have shown that players are passing their on-field expiration dates earlier—not just compared to the steroid era but also compared to the first decade after PED testing was instituted. As the baseball writer Joe Sheehan put it in 2023, “It’s harder than ever for players to hold their value in their thirties. … The aging curve is now an aging slope.” Maybe that’s why a then-35-year-old Brandon Belt barely drew interest after a fine 2023, why Jose Iglesias (35) and Mark Canha (36) initially settled for minor league deals this offseason, and why productive veterans such as David Robertson (39), Lance Lynn (37), and Yasmani Grandal (36) are still unsigned.
The corollary to older players producing worse, in a relative sense, is younger players producing better. As Sheehan also wrote, “Baseball is a young man’s game now. … Players arrive in pro ball more ready to play at the highest level than they ever have before.” Thus, rapid promotions would seem to make sense. Sure enough, teams have increasingly called up youngsters at the start of seasons—egged on by new incentives in the current collective bargaining agreement—and in some recent years, those precocious prospects have hit the ground slugging at historic clips. The average time in the minors before big league debuts has dropped, and the average age of MLB batters has fallen by a full year since 2010.
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On the other hand, there’s a somewhat confusing caveat to that corollary. Young players are, as Sheehan wrote, “more advanced than they have ever been,” yet allegedly, they’re also having a harder time advancing. The difficulty gap between the minors and majors is growing, many media members, players, and front office folks say, and as a result, the transition from Triple-A to MLB has reached peak peril.
This assertion seemed to crystallize into common knowledge last year, in a string of reported pieces:
The Athletic (May 9): “Why Top Hitting Prospects Are Having a Harder Transition to the Majors Than in the Past”
The Athletic (July 1): “As Gap Between Triple A and MLB Widens, Is the Minor League Reset Fading Away?”
The Score (August 14): “Growing Gap Between Majors and Minors Makes Graduating Hitters Harder”
Defector (August 27): “The Minor League Shrink and the Growing Gap Between Triple-A and the Bigs”
As FanGraphs writer Ben Clemens said on my baseball podcast last July, in reference to slow-starting Rangers prospect Wyatt Langford, “I’ve seen a lot written about this this year, and I think it’s true—the gap between the minors and the majors is larger than before, and you do have to really think, ‘Ah, man, maybe he can’t hit it in the majors like he could in the minors.’”
For the most part, the articles above, well sourced though they were, based their cases on anecdata, highlighting—or lowlighting—a small group of hitters whose swift ascents spiraled into rapid unscheduled disassemblies. Prime among them was the Orioles’ Jackson Holliday, a no. 1 overall draft pick and prospect who looked completely overmatched in his first major league trial last April—he struck out in 18 of 36 plate appearances, with two singles and two walks—and never really got going when he returned from a Triple-A retreat in late July. (Overall, his 63 wRC+ ranked 24th worst among 365 hitters with at least 200 trips to the plate.) Holliday was undoubtedly disappointing, but he’s only one (21-year-old) man. Of course, it’s easier to focus on the exploits or struggles of a few famous prospects than to quantify the relative strengths of entire rungs of the sport’s professional ladder. But it can be done, or at least approximated.
With more comprehensive information in mind, should teams pump the brakes on promoting prospects? Should fantasy owners bump them down their draft boards? Is moving from the minors to the majors actually harder than ever? Yes … sort of. But the degree of added difficulty and its impact on player development have probably been overblown.
There are valid reasons to think that the caliber of baseball—and pitching in particular—at the sport’s top tier might be pulling away from Triple-A. Data-driven advance scouting, powered by Statcast, may have improved in the majors more than the minors, allowing teams to target hitters in the majors more effectively at the plate or in the field. Minor league teams now play six-game series, twice as long as the standard series in the majors, which gives hitters longer looks at opposing pitchers. Teams tend to promote promising pitchers more quickly than promising hitters—partly because it’s easier to evaluate and develop pitchers with fewer reps and partly because the clock is always ticking on young hurlers’ health. Stringent minor league roster limits have driven older, close-to-big-league-quality players out of the sport or to unaffiliated circuits such as the Mexican League. And over the past two seasons, the ball-strike challenge system and full ABS have been tested in Triple-A, pumping up walk rates and scoring and forcing hitters to readjust to human umps when they make the majors.
Despite all of those obstacles, though, rookie hitters, as classified by FanGraphs, haven’t gotten any less productive on the whole, relative to the MLB baseline. Over time, rookie hitters have tended to be about 85 percent as potent, on a rate basis, as major league hitters (with sporadic spikes, as well as a low ebb during the steroid era, when older players showed unnatural longevity). They’ve cleared that bar in each of the past three seasons, coming in at 88 percent last year.
Some of the highly touted rookies whose early struggles last season spurred that fretting about the minors-to-majors adjustment—Jackson Merrill, Jackson Chourio, Langford, Colt Keith—recovered quickly and finished strong, as 2023 Rookie of the Year Gunnar Henderson had in the preceding season. And some successful rookies—Tyler Fitzgerald, Austin Wells, Wilyer Abreu—weren’t really on the radars of most fans before the season started. Maybe the hiccups we saw from some rated rookies were manifestations of an expanding Triple-A-to-MLB chasm … or maybe they were the same old small-sample issues some future greats have had upon making the majors since time immemorial. Heck, in any given spring, some established stars catch a cold at the plate: Francisco Lindor batted .032/.184/.032 in his first 38 plate appearances last season. He didn’t boost his batting average above .100 until his 13th game, but he’d finish second in the NL MVP race.
On a macro level, then, rookie hitter quality has barely budged. Here’s what has changed dramatically: the offensive environments in Triple-A and MLB.
The chart below shows the average OPS in MLB by year, along with the average figures for the two Triple-A leagues, the International League, and the Pacific Coast League.
We can clean that up a little by combining the two Triple-A leagues:
See all that white space between the recent Triple-A and MLB figures? We can make that even clearer by graphing the gap between each year’s Triple-A and MLB OPS:
Last year, the average OPS in MLB was about 87 points lower than the average OPS in the PCL, 52 points lower than the average OPS in the IL, and 64 points lower than the average OPS in both Triple-A leagues combined. To put that into perspective, the offensive difference between the IL and MLB was roughly equivalent to the offensive difference between Fenway Park (the second-most offense-inflating environment in the majors) and a neutral MLB park. The difference between the PCL and MLB was akin to the difference between Coors Field (the most offense-inflating stadium) and a neutral MLB park.
Triple-A offense has almost always been higher than MLB offense, thanks largely to the PCL’s long-standing status as a hitter’s haven. Historically speaking, though, these are unusually large differences—sizable enough to distort our perception of player performance when a Triple-A player is promoted to MLB. In a sense, this supports the observation that there’s a growing gap between Triple-A and MLB: It is actually harder to hit in MLB these days. Crucially, though, it’s harder to hit for everyone, not just for players who are making the majors for the first time.
If a major league player moved from an offense-inflating park like Coors or Fenway to an offense-suppressing park, we wouldn’t expect them to post the same statistics in their new surroundings, even if they continued to play just as well. We also wouldn’t think that they’d forgotten how to hit or that their Achilles’ heel had been exposed if their surface stats sank. We would adjust their numbers to account for the context in which they were produced. Therefore, we should do the same for a player promoted from the minors to a less hitting-happy league. As Orioles GM Mike Elias said last spring, “You can’t just look at somebody’s Triple-A stats and imagine those stats in the majors and that’s how it’s going to go.” You have to forecast that their results will suffer somewhat, even if their process stays the same, because conditions in the majors are currently less conducive to offense across the board.
For instance, take Cardinals shortstop Masyn Winn. At Triple-A in 2023, he hit .288/.359/.474, good for an .834 OPS. In MLB in 2024, he hit .267/.314/.416, good (but seemingly less good) for a .730 OPS. That’s a decline of 104 points, which sounds like a lot: It’s the same as the difference last season between Winn and Jarren Duran, an All-Star and top-10 MVP vote getter. But the average OPS in the International League in 2023 was .794, 83 points higher than the average OPS in the majors last year (.711). Thus, relative to the league, Winn’s OPS decline was a much more modest 21 points, which was reflected in his slight dip per league-adjusted stats (a 108 wRC+ to a 103 wRC+).
Alternatively, consider Rangers third baseman Josh Jung. In 2022, Jung hit .273/.321/.525 (.846 OPS) in 23 games in Triple-A. In the majors in 2023, he hit .266/.315/.467 (.781)—a respectable slash line, but 65 points worse. If you factor in the leagues he was in, though, it wasn’t worse at all. In 2022, the average OPS in the Pacific Coast League was .804; in 2023, the average OPS in MLB was .734. Relative to the league, he actually improved, as indicated by his wRC+ uptick from 104 to 112.
Now, no amount of stat adjusting can salvage Holliday’s major league stats as a rookie or explain the 343-point gap between his Triple-A and MLB OPS figures last season. For whatever reason, his hitting did crater. (I expect a much more robust sophomore season.) What we need is a method more powerful than cherry-picking outliers—a method that can incorporate many more players and measure not just how productive a rookie class was but also how productive it was given its prior, Triple-A performance. (After all, some rookie classes are more or less stacked than others.)
Luckily, we have one. FanGraphs writer Dan Szymborski, creator of the ZiPS projection system, sent me data on every hitter from 1977 through 2024 who made at least 200 plate appearances in both Triple-A and MLB in the same season or in consecutive seasons. He neutralized the stats at both levels—that is, removed the artificial influence of a player’s surroundings so that stats in one league can be compared to stats in another league on a more equal footing, free of the effects of extreme scoring environments. In 2022, Mariners executive Justin Hollander described the performance hit a prospect endures after making the majors as a “transition tax.” This, then, is a way to isolate the true transition tax that stems from the player’s performance and the competition he takes on.
Here’s what this looks like leaguewide by year, as expressed in runs created per 27 outs. The higher the percentage, the narrower the gap between Triple-A and MLB. The average across all years is 80 percent: After adjusting for context, about 80 percent of hitters’ production survived their transitions from Triple-A to the majors. In other words, Triple-A has historically been roughly 80 percent as “hard” as MLB.
In any given year, the sample of applicable players isn’t all that large. (It’s especially small for 2019 and 2024 because the 2020 minor league season was canceled and the 2025 season has yet to be played, which limits us to same-season promotions.) So here’s a smoother version that lumps together groups of three seasons:
Over this roughly 50-year period, the strength of Triple-A relative to the majors has fluctuated within a fairly narrow range, from about 76 percent of MLB to about 86 percent. It’s certainly at the low end of that range now, so it’s fair to say that the Triple-A-to-MLB leap has never been more daunting. We see the same trend for promoted pitchers’ ERAs, though in that case, entering a higher-level league makes ERAs go up. (Once we adjust for the fact that the Triple-A scoring environment is much more hitter friendly than MLB’s.)
The thing is, these effects are subtle, which is why I said it’s “sort of” true that moving from the minors to the majors is harder than ever. It is, but only by a few percentage points—probably not by enough that anyone would make much of it, if not for the much more salient, albeit superficial, effects of offensive flood tides and ebb tides lifting or lowering all bats in leagues across multiple levels.
This jibes with what one major league front office analyst tells me. “I went poking around and could never really find especially compelling evidence that rookies are struggling to a disproportionate degree,” he says. “It feels like they are, but they aren’t, and maybe we just notice more when they struggle because there are more young players and fewer veterans than ever these days. The pitching gap has definitely widened between Triple-A and MLB, and that does have an effect, but said effect appears greatly overstated.”
Here’s the twist: I wrote essentially this same article, using the same methodology, with almost the same conclusions, in response to the same sort of then-new trend pieces, almost exactly 10 years ago (in February 2015). Then, as now, offense in the minors was high compared to offense in the majors, where the lively ball of the mid-2010s had not quite come into play. The buzz about a growing minors-to-majors transition tax subsided when MLB home run rates reached record levels, bringing the league’s scoring more closely in line with Triple-A’s. But once the ball was deadened and scoring headed downhill, the hand-wringing returned.
Some prospects do have hidden holes that major league scouts and players pick apart in ways that Triple-A opponents can’t. It must feel frustrating for hitters to go from feasting on minor league arms to facing baseball’s best of the best—and some top prospects who’ve been great from the get-go aren’t used to feeling frustrated on the field. (Fans also can’t forget the times when one of their team’s possible saviors fizzled at first blush.) But the notion that the minors-to-majors transition has gotten far harder for hitters seems mostly to be a mirage caused by the cratering of MLB offense overall. Adjusted for context, good young hitters, on the whole, handle the majors almost as well (or as poorly) as ever. Which means that the oldsters must make way for the kids because they’re just going to keep coming. It’s the circle of athletic life.
Thanks to Dan Szymborski of FanGraphs and Kenny Jackelen of Baseball-Reference for research assistance.
