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The Era of Breakout Batters

Your mind’s not fooling you—there are more fresh faces having their first great offensive season in the past few years than at any point in the game’s history

Getty Images/Ringer illustration

On Monday night in Cleveland, the Mets’ Pete Alonso launched 23 dingers in the final round of the MLB Home Run Derby, edging out the Blue Jays’ Vladimir Guerrero Jr., who managed 22 more after setting single-round records with 29 in the quarterfinals and 40 in the semis. Together, rookies Guerrero and Alonso accounted for 148 of the 312 deep flies in the Derby, which means that nearly half of the homers were hit by players who made their major league debuts in 2019.

It’s fitting that recent arrivals dominated the Derby, because nothing could be more emblematic of MLB’s recent regular seasons than fresh faces doing damage at the plate. The upper reaches of this year’s offensive leaderboards feature an abnormal number of full-time hitters who haven’t been there before—except that what was abnormal for the past few decades might be the new normal now. In an era defined by a vast influx of young talent, a juiced ball, and data-driven player development, baseball forces fans to be flexible, attentive, and diligent about updating their mental lists of potential league leaders. Even more so than it once was, the first half of the season is a time to get our bearings and recalibrate our beliefs about who the best batters in baseball might be.

This season, 32 hitters who qualified for the batting title entered the All-Star break with a wRC+ of 130 or higher—that is, a performance at the plate that put them at least 30 percent above the league average. Let’s call them the offensive elites. Of those elite 32, 17—53 percent—have never had a full season in which they qualified for the batting title and finished with a wRC+ that high.

Now, there’s always plenty of turnover among league-leading hitters: Guys regress, guys get hurt, guys (like Alonso) go from leading the minors in homers one year to making the majors and mashing there the next. There’s even more turnover if we compare the previous season to the current season at the All-Star break, because we haven’t had a full-season sample for the stats to settle down: In the second half (or, this year, the last 44.7 percent) of the regular season, some fast starters will slow down and some slow starters will speed up. Even so, for 53 percent of the elite regulars at this point in the season never to have finished a previous campaign in that august group—well, that’s weird. Almost unprecedented, actually. And the only recent precedent is part of the present era also.

The graph below shows the percentage of first-timers among the elite hitters at the All-Star break in each season back to 1974—the first year that we have accounts of every game from Retrosheet and first-half/second-half splits at FanGraphs.

Clearly, this rate tends to bounce around. But this year’s percentage is the second-highest in this 46-season span—and the only higher rate occurred in 2017. From 2016 through 2019—the first four full seasons of this juiced-ball period—the annual turnover rates haven’t fallen lower than 44.4 percent. At no previous point in the 46-season sample did the turnover rate stay higher than 40.5 percent in two consecutive years, let alone 44.4 percent in four consecutive years. Only nine seasons in the sample have featured turnover rates of 44.4 percent or higher, and five of them have come in the last six years. If we break this down by decade (excluding the strike-shortened first halves in 1981 and 1995), the difference seems clear.

First-Half Elite-Hitter Turnover Rate

Decade Turnover Rate
Decade Turnover Rate
1970s 34.20%
1980s 35.80%
1990s 33.70%
2000s 36.50%
2010s 45.00%

One might wonder whether the All-Star break is occurring earlier in the season than it did in the past, which could create more turnover due to smaller samples. Nope: Qualified hitters averaged 340.5 plate appearances in this first half and 344.0 PA in first halves from 2016 to 2019, slightly more than the 331.0 they averaged from 1974 to 2015.

The table below lists the 17 first-timers among the elites this season. Again, these players have never hit at least 30 percent better than the league average while playing full-time over a full season, but they did both through the first half, establishing themselves as breakout players or demonstrating that some earlier smaller-sample success was sustainable. Their origin stories are different, but the upshot is the same: They’re all on track to do something they haven’t accomplished previously, although some will likely dip below a 130 wRC+ between now and October (or miss enough time to fall short of qualifying for the batting title).

First-Timers: 2019 Qualifying First-Half Hitters With a ≥130 wRC+

Name Age Team PA wRC+
Name Age Team PA wRC+
Pete Alonso 24 Mets 376 161
Josh Bell 26 Pirates 388 156
Jeff McNeil 27 Mets 318 147
Juan Soto 20 Nationals 342 143
Rhys Hoskins 26 Phillies 392 142
Willson Contreras 27 Cubs 302 141
Yoan Moncada 24 White Sox 336 139
Luke Voit 28 Yankees 349 139
Daniel Vogelbach 26 Mariners 341 138
Rafael Devers 22 Red Sox 378 137
Max Muncy 28 Dodgers 358 135
Ketel Marte 25 Diamondbacks 384 133
Hunter Renfroe 27 Padres 289 133
Hunter Dozier 27 Royals 286 133
Yasmani Grandal 30 Brewers 341 130
Gleyber Torres 22 Yankees 340 130
Austin Meadows 24 Rays 305 130

The next five qualifying hitters below 130 on the wRC+ leaderboard—Jorge Polanco, Domingo Santana, Ronald Acuña Jr., Brandon Lowe, and Tommy La Stella, all of whom are at 129 or 128—all would have been first-timers, too. And if we’d kept the wRC+ bar at 130 but lowered the first-half playing-time minimum to 200 PA, several other potential first-timers would have leaped onto the list: Joey Gallo, Fernando Tatís Jr., Lourdes Gurriel Jr., Bryan Reynolds, Shohei Ohtani, Howie Kendrick, Carlos Correa, Mark Canha, James McCann, Matt Olson, and Omar Narváez. In other words, it’s not as if every new hitter anywhere near the vicinity of a 130 wRC+ or enough plate appearances to qualify for the batting title just happened to creep across those thresholds this year; there were many more like them who narrowly missed the list. So what’s whipping up the cream of the offensive crop?

The Youth Movement

It’s not surprising that Yasmani Grandal (who’s come close to cracking this club before) is the only hitter on the table above who’s older than 28. Odds are that if a hitter has what it takes to post a 130 wRC+ for half a season, he’s going to do it for the first time in his 20s, when he’s in his physical prime. But that’s not all that’s happening here. It became clear about five years ago—roughly the time that the first-half turnover rates among elite hitters spiked—that teams were gravitating toward youth, and that trend has intensified since. As a headline on an article about young hitters by ESPN’s Sam Miller proclaimed last December, “Young Players Have Officially Taken Over Major League Baseball.”

Last summer, then–Orioles outfielder Adam Jones told Miller, “The next generation’s here, and they’re really good.” Jones, who was really good not that long ago (although his wRC+ topped out at 127), was all of 32 at the time, but the game’s next generation was making him feel (and look) old. MLB is a zero-sum environment, and when a wave of young hitters crests, some older hitters are going to get caught in the ensuing crash. It’s been more than half a century since the gap between 25-and-under hitters and 35-and-over hitters was consistently as wide as it’s been in recent seasons.

This year, MLB’s average hitter age, weighted by WAR—so that better players exert more influence over the average—has fallen to 27.37, which would be a new low for the DH era, coming in slightly below last year’s figure, which was itself a new low at the time.

At the top of the leaderboards, then, the pattern in recent seasons has been out with the old and in with the new. Instead of former staples such as Joey Votto, Paul Goldschmidt, and Miguel Cabrera, we’re seeing new names, like the 24-and-under Alonso, Soto, Moncada, Devers, and Torres. It used to be typical for hitters to take time to adjust to the majors, but it’s increasingly common for them to excel almost as soon as they get there. The aforementioned five youngsters are all former blue-chippers whom prospect hounds have tracked for years; but for fans who don’t follow the minor leagues closely, each spring is now a period of exciting discovery (or rude disruption) as the sport’s need-to-know names are reshuffled.

The Juiced Ball

In mid-2015, home run rates skyrocketed, and they’ve kept climbing since. We now know for certain that changes to the ball are primarily responsible, and this year’s flat-seamed, smooth-surfaced ball is flying even farther than the already-aerodynamic model from the past few years. Barring another sudden and dramatic midseason change, MLB will leapfrog the single-season home run record set in 2017 sometime this summer.

It’s probably not a complete coincidence that the highest first-half turnover rates among elite hitters since at least the early ’70s coincided with the two highest home run rates in the history of the sport. 2017 also saw the lowest year-to-year correlation in full-season wRC+ of the entire expansion era among all hitters who made at least 400 plate appearances in both 2016 and 2017, signifying greater fluctuation in performance. There, too, we see a decadal trend toward less consistency (again omitting strike-affected seasons, as well as the current, incomplete campaign).

Year-to-Year Correlation in wRC+ (Min. 400 PA)

Decade Average Correlation
Decade Average Correlation
1960s 0.66
1970s 0.62
1980s 0.58
1990s 0.61
2000s 0.62
2010s 0.51

It’s true that all players are subject to the same ball in any given season, but that doesn’t mean they all benefit from a juiced one to the same extent. If a ball that flies farther makes batted balls in the air more advantageous, then all else being equal, hitters who launch the ball upward more often will enjoy a disproportionate improvement. What’s more, hitters who produce a certain type of fly ball might benefit the most. As Jeff Sullivan wrote for FanGraphs in September 2016:

The strongest hitters just don’t stand to benefit so much from a distance increase, because they would hit relatively few “almost-homers.” The weakest hitters also wouldn’t benefit too much, because they would seldom challenge the warning track. But those guys with warning-track power would benefit the most, because then it’s just a matter of a few feet turning an out into a dinger. The marginal value of an extra few feet for a player with average power surpasses the marginal value of an extra few feet for a player with tremendous power, or for a player with zero power.

Consequently, the new ball may have helped players who’d previously belonged to the middle class of home run hitters unexpectedly vault into elite territory. Sure enough, several formerly mediocre players in their late 20s or early 30s made leaps like that in the first half of 2017.

First-Timers: 2017 Qualifying First-Half Hitters With a ≥130 wRC+

Name Age Team PA wRC+
Name Age Team PA wRC+
Aaron Judge 25 Yankees 366 197
George Springer 27 Astros 378 166
Carlos Correa 22 Astros 363 163
José Ramírez 24 Indians 361 155
Michael Conforto 24 Mets 273 149
Marcell Ozuna 26 Marlins 372 147
Yonder Alonso 30 Athletics 298 147
Justin Smoak 30 Blue Jays 333 146
Cody Bellinger 21 Dodgers 292 144
Logan Morrison 29 Rays 346 143
Zack Cozart 31 Reds 284 142
Justin Bour 29 Marlins 305 140
Travis Shaw 27 Brewers 332 139
Corey Dickerson 28 Rays 370 139
Eric Thames 30 Brewers 329 138
Steven Souza, Jr. 28 Rays 361 136
Josh Reddick 30 Astros 299 136
Miguel Sanó 24 Twins 345 136
Trey Mancini 25 Orioles 280 135
Jonathan Schoop 25 Orioles 352 132
Eric Hosmer 27 Royals 366 130
Jay Bruce 30 Mets 356 130

Even though the leaguewide dinger rate has never been higher, the game’s greatest sluggers aren’t challenging single-season home run records. Instead, we’ve seen a significant democratization of dingers: No one is hitting 60, but many more players are hitting 20 or 30. That means more hitters have a chance to ascend into a stratosphere that once was reserved for established stars whose size and set of skills are no longer prerequisites for raking.

Improvements in Player Development

MLB is enmeshed in the early stages of a player-development revolution driven by data and new technology, which players have harnessed to make the most of their talent. As Baseball Prospectus writer Rob Arthur recently showed, pitchers have grown more willing to make major adjustments to their repertoires as the science of pitch design has progressed and a deeper understanding of what makes pitches effective has overcome the fastball-first mentality that prevailed in the past.

It’s harder to assess how hitters have changed because precise public batted-ball data didn’t become available until 2015. But we know that the league’s average launch angle has increased in every season since, and many hitters—including some who were already really good—have made major gains by embracing the gospel of balls in the air and using tools such as swing sensors, force plates, and other body- and ball-tracking technology to make mechanical changes that allowed them to tap into their power. If a 35-year-old Hunter Pence can visit an outside swing whisperer and return to an All-Star level after a few injury-plagued, unproductive seasons, it shouldn’t shock anyone that a 10-years-younger physical specimen such as Josh Bell could consult a coach of his own and terrorize opposing pitchers for the first time. As Mariners director of player development Andy McKay told me last year, “This player-development technology is going to provide enough information that the players that are willing to go for it can make quantum leaps in their careers.”

Mechanical overhauls that work wonders at first aren’t always permanent panaceas. (See: once-successful swing-changer Yonder Alonso—or don’t, because he’s currently unemployed.) If anything, it’s getting harder to hit much better than average in an era when the caliber of competition is higher than ever, which tends to compress the range of statistical performance because the best players don’t have truly terrible players to feast on. Perennial Silver Slugger contenders are fewer and farther between: Eight-time All-Star Mike Trout, who won’t turn 28 until next month, boasted the most career Midsummer Classic appearances of any position player on this year’s All-Star rosters, and 36 of the 75 players named to the team—48 percent—had never been All-Stars before.

From a marketing perspective, that turnover presents a challenge. But it also presents an opportunity to get the audience acquainted with baseball’s new blood. “I think it’s a generational shift, and we’re really fortunate that the group that’s coming along is diverse, extraordinarily talented, and really appealing from a personality perspective,” commissioner Rob Manfred told me in 2015. Instead of one face of the game, he added, “I want to have 10 faces of the game.” At this rate, baseball is making more faces than the House of Black and White.

In recent seasons, baseball’s nigh-indestructible superteams have made the standings seem somewhat static. All seven of the teams that FanGraphs’ preseason projections gave better-than-even odds of playing into October still have playoff odds above 50 percent. Even so, there’s no shortage of WTF-worthy outcomes in the season so far. If variety really is the spice of life, then the top of baseball’s batter leaderboards are extra-hot habanero.

Thanks to Jessie Barbour for research assistance.