The Rookie of the Year Award isn't like some of baseball's other accolades -- there are no minimum qualification restrictions, like there are for the batting title, so rookie phenoms who make a huge impact in a short time can still win it.
Here are the Rookies of the Year who won the award in the least amount of time in the Majors.
There's only a small group of Rookie of the Year Award-winning position players who logged fewer than 400 plate appearances. Rays 20-year-old phenom Wander Franco almost joined the group in 2021, but his teammate, Randy Arozarena, won the award instead.
This is the list, in ascending order of plate appearances.
(We’ve placed asterisks next to winners Shohei Ohtani and Bob Hamelin simply to point out the extenuating circumstances. Ohtani was recognized for his terrific work as both a hitter and a pitcher, while Hamelin’s plate-appearance total -- and entire season -- was cut short by the 1994 strike. We're also excluding 2020 AL Rookie of the Year Kyle Lewis from the list, as his 242 PAs came in a pandemic-shortened 60-game season).
Willie McCovey (Giants), 1959 NL
Total plate appearances: 219
McCovey was hitting .372 with 29 homers in Triple-A before he was called up, and his first Major League game saw him go 4-for-4 with two triples against future Hall of Fame pitcher Robin Roberts. "Stretch" continued maximizing each time he had a bat in his hands: He only appeared in 52 games, but he averaged one home run for every four of them while batting .354 and recording a 22-game hit streak. Thirteen of McCovey’s 38 RBIs gave the Giants a lead, and there were even complaints that he didn’t appear in that summer’s second All-Star Game -- staged four days after his big league debut.
Ryan Howard (Phillies), 2005 NL
Total plate appearances: 348
Howard’s power was self-evident, both from his 6-foot-4, 250-pound frame and by becoming only the fifth Minor League player to hit at least 46 homers in a season as he pummeled Double-A and Triple-A pitching in 2004. Jim Thome’s early-season injury opened the door for Howard at the Phillies’ first-base position, and he survived rumors at the Trade Deadline to become a force down the stretch. The Missouri native slugged 11 homers and drove in 27 runs in September and October, helping Philadelphia make a late run before falling just shy of the Braves in the NL East.
Howard easily cleared Houston’s Willy Taveras for Rookie of the Year honors with 22 homers and 63 RBIs over just 88 games, and he would capture his lone MVP Award the following year.
Bob Horner (Braves), 1978 NL
Total plate appearances: 359
Horner won the inaugural Golden Spikes Award, given to the nation’s top amateur player, in 1978 with Arizona State and then went first overall to the Braves in that summer’s MLB Draft. He bypassed the Minors entirely and found himself in Atlanta’s lineup just nine days after the Draft, living up to the hype immediately by homering off future Hall of Famer Bert Blyleven at 20 years old.
“When he swings, he lets it out,” Blyleven told The Associated Press. “He doesn’t give any half-swings. He impressed me.”
Horner went on to knock 23 long balls across 89 games, pacing all NL third basemen -- rookies or not. He hit just .213 after his first 20 games as a big leaguer, then hit .282 with 21 dingers over his last 69 games to take NL rookie honors over Ozzie Smith.
Shohei Ohtani (Angels), 2018 AL
Total plate appearances: 367*
Ohtani’s plate appearances were limited, yes, but we’d be remiss if we didn’t immediately point out that he also faced 211 hitters from the pitcher’s mound, striking out 63 of them while compiling a 3.31 ERA with triple-digit heat and a devastating slider. Topping the Yankees' Miguel Andujar for the award, Ohtani truly was an anomaly, becoming the first player since Babe Ruth in 1919 to pitch 50 innings on the mound and club at least 15 homers at the plate.
Ohtani was mighty impressive just as a hitter: He finished with 22 dingers in 326 at-bats, and his .564 slugging percentage was seventh-best among all Major League hitters who made 300-plus trips to the plate. He underwent Tommy John surgery at season’s end, but his days as a two-way star were far from over.
Yordan Alvarez (Astros), 2019 AL
Total plate appearances: 369
The Dodgers had signed Alvarez, a Cuba native, in 2016 but soon traded him to Houston for reliever Josh Fields. That quickly became an outstanding move for the Astros, as Alvarez destroyed Triple-A pitching before getting called up on June 9, 2019, shortly before his 22nd birthday. He promptly homered in both of his first two games and seven of his first 12. Alvarez never really slowed down, slashing .313/.412/.655 with 27 homers and 78 RBIs in 87 games for the AL pennant-winners. His park-adjusted 173 OPS+ ranked third among all MLB hitters (minimum 300 PAs), behind only Mike Trout and Christian Yelich, and set a Modern Era (since 1900) AL/NL rookie record. Given that, Alvarez was an easy choice for voters, who made him a unanimous selection.
Wil Myers (Rays), 2013 AL
Total plate appearances: 373
Myers enjoyed one of the best "told-you-so" seasons in recent memories, capturing the AL’s top rookie honor right after the Royals traded him to the Rays for starter James Shields and closer Wade Davis during the previous offseason (Kansas City, for its part, captured back-to-back pennants and a World Series title in 2015 with Davis in the back of the bullpen). The highly touted Myers didn’t make his way up to Tampa Bay’s lineup until June 18, and yet he still managed to lead AL rookies with 53 RBIs across 88 games -- the first AL player to lead rookies in that category while playing fewer than 90 contests since 1946. That also helped Myers become the Junior Circuit’s first Rookie of the Year Award winner while logging fewer than 100 ballgames.
Bob Hamelin (Royals), 1994 AL
Total plate appearances: 375*
Hamelin was a two-sport star who turned down Notre Dame’s overtures to play football and concentrate on baseball. Royals icon George Brett retired in 1993, but Hamelin gave Kansas City fans a thrill the following summer, earning the nickname “The Hammer” as he broke Bo Jackson’s franchise rookie home run record with 24 dingers in just 312 at-bats while also driving in 65 runs. At age 26, Hamelin was a Rookie of the Year Award winner, soundly beating out Manny Ramirez in a strike-shortened season.
Hamelin’s star faded as quickly as it arrived; he would just seven homers the following season and finished with 67 as a big leaguer before he retired in the middle of a Minor League game in the summer of 1999.
Al Bumbry (Orioles), 1973 AL
Total plate appearances: 395
Bumbry actually attended Virginia State College on a basketball scholarship; he didn’t play baseball until his senior year, when he joined the team and hit .578. That was enough to catch the eye of the Orioles, who drafted him in the 11th round in 1968 and convinced him to stick to the diamond after the NBA didn’t come calling. Bumbry served in the Vietnam War and then returned in 1971, when he batted .336 at Class A. He then hit .345 the following year at Double-A and Triple-A and captured the International League’s Player of the Year Award.
Orioles manager Earl Weaver called Bumbry the fastest player he’d ever seen, and he wreaked havoc as Baltimore’s rookie platoon outfielder in 1973, pacing the AL with 11 triples and stealing 23 bases in just 110 games while also batting .337. That made him the Junior Circuit’s runaway Rookie of the Year Award winner as Baltimore finished a game shy of reaching the World Series.