There's a unique excitement when a rookie shines in his debut season, or a recent acquisition via trade or free agency is prolific right out of the gate for his new team. Throughout baseball history, there have been records set, championships won, and unforgettable memories created during a player's first season with a club. Some of these guys went on to All-Star and/or Hall of Fame careers, but this is where they made their first impression with a new fanbase. Here's a look at each club's best individual debut season, from surprising rookies to big-ticket free-agent signings.
AMERICAN LEAGUE EAST
BLUE JAYS: Josh Donaldson, 2015
Donaldson’s arrival in 2015 was the perfect marriage of individual performance and team success. Following a 22-year playoff drought, the Blue Jays made a big bet on the third baseman, whom they acquired over the offseason from the A’s as part of a package of talented young Major Leaguers and prospects.
Donaldson delivered, as he always does, winning the club’s first AL MVP Award since George Bell in 1987. Along with the stellar defense and leadership that Donaldson brought to the team in 2015, he posted a .939 OPS with 41 home runs and 123 RBIs. The Blue Jays have seen plenty of incredible debuts beyond Donaldson, including Roger Clemens' 1997 campaign, for which the right-hander won a Cy Young Award with a 2.05 ERA over 264 innings, but that team finished 10 games below .500. -- Keegan Matheson More >
ORIOLES: Frank Robinson, 1966
It’s hard to make a better first impression than the one Frank Robinson made for the Orioles, who were looking for a difference maker in the winter of 1965 to catapult their emerging team to the next level. What they got was an icon, a singular figure who’d go on to change the entire trajectory of the franchise.
Arriving in Baltimore from the Reds in the lopsided deal for right-hander Milt Pappas, Robinson wasted little time. He won the AL Triple Crown the following season, pacing the league in runs (122), on-base percentage (.410), slugging ( .637) and total bases (367) as well as hitting (.316), homers (49) and RBIs (122). He led the Orioles to their first World Series, earning MVP honors in their sweep over the Dodgers that October. He was also the unanimous selection for AL MVP. -- Joe Trezza More >
RAYS: Carlos Peña, 2007
In his first six seasons in the Majors, it was obvious that Peña was very capable of hitting the ball out of the ballpark. Despite hitting 86 homers over that span, Peña struggled to find a consistent home, playing for four franchises (Rangers, A’s, Tigers and Red Sox).
But in ‘07, Peña found his permanent home in Tampa Bay after signing a Minor League deal, and immediately became a star. In his first season with the Rays, he crushed 46 home runs, a single-season record that still stands today. He drove in 121 runs and posted a .627 slugging percentage, both single-season team records.
The ‘07 season was the beginning of a dominant four-season run that established Peña as the best first baseman in franchise history. From ‘07 to '10, Peña hit 144 home runs, drove in 407 runs, posted a .884 OPS, and helped the Rays win their first American League pennant in '08. -- Adam Berry More >
RED SOX: Ted Williams, 1939
There was no easing into the Major Leagues for this all-time legend. Williams arrived in Boston for the 1939 season and became a superstar as a rookie. He had a line of .327/.436/.609 with 44 doubles, 11 triples and 31 homers while leading the league in RBIs (145) and total bases (344). The sweet-swinging left-handed hitter finished fourth in MVP voting that season.
The Red Sox went a respectable 89-62 in '39, but finished 17 games behind a powerhouse Yankees team in the AL. The 6.8 WAR by Williams in '39 is the most ever by a Red Sox position player in his first year as a Major League player. Just two years later, he hit .406. In a career that ended in 1960, Williams never stopped hitting. In fact, he hit a home run in his final at-bat in the Majors. -- Ian Browne More >
YANKEES: Babe Ruth, 1920
There have been fantastic Yankees debut seasons within recent decades -- Rickey Henderson (1985), Catfish Hunter (1975) and Reggie Jackson (1977) among them -- but it's nearly impossible to top the impact that Ruth made upon joining the Yanks for the 1920 campaign.
Converted into a full-time outfielder, Ruth's 54 home runs not only led the Majors, they were more than every other AL team -- and all but one other big league squad (the Phillies combined for 64 homers that year). As more than 1.2 million fans passed through the Polo Grounds' turnstiles for a peek at the Sultan of Swat, Ruth also led the Majors in runs (158), RBIs (135), walks (150), on-base percentage (.532), slugging percentage (.847) and OPS+ (255) while batting .376 in 142 games, producing a staggering WAR (Baseball Reference) of 11.8 -- a mark he’d surpass in three subsequent seasons. -- Bryan Hoch More >
INDIANS: Andrew Miller, 2016
His debut season may only have been half of a season, as the lefty reliever was traded to the Indians from the Yankees on July 31, but the impact Miller made on his new club was unmatched. Cleveland shocked the baseball world by parting with two top prospects (Justus Sheffield and Clint Frazier), but what it got in return was a 1.55 ERA in 26 outings with 46 strikeouts, a 1.53 FIP, 0.55 WHIP and an ALCS MVP Award winner. In just 29 innings, Miller was able to accumulate a 1.1 WAR (Baseball Reference).
Miller was thrown into the middle of a pennant race and became a force out of the bullpen. His 11 2/3 scoreless frames through the Division and Championship Series led the Tribe to the World Series, and he went on to toss two more scoreless outings before he gave up one run in Game 4 and two in Game 7. Even if the criteria required a full season, Miller could take that title again, as he came back in his first full season with the Tribe in '17 with a 1.44 ERA in 62 2/3 innings with 95 strikeouts and a 0.83 WHIP before the rest of his time with the Tribe was marred by injuries. -- Mandy Bell More >
ROYALS: Danny Tartabull, 1987
Acquired in a trade with Seattle the previous December, Tartabull had a monster season in his first year with the Royals. He played in 158 games and hit 27 doubles with 34 home runs and 101 RBIs. If that wasn’t enough, how about a .931 OPS? And remember, this is when then Royals Stadium’s dimensions were at today’s cavernous dimensions [the Royals moved the fences in 10 feet from bullpen to bullpen from 1995-2003]. Tartabull had a remarkable five-year offensive stint with the Royals, clubbing 124 home runs. His '91 season was even better -- he led MLB with a .593 slugging percentage and made the All-Star team. -- Anne Rogers More >
TIGERS: Mark Fidrych, 1976
While other Tigers had comparable statistical seasons -- Iván Rodríguez’s 2004 campaign comes to mind -- nobody had an immediate impact quite like Fidrych. Not only did "The Bird" earn AL Rookie of the Year honors in 1976, he became a cultural phenomenon with his lanky frame, big hair, aw-shucks personality and pitching antics.
All the eccentricities overshadowed the fact that the 21-year-old Fidrych, despite one full season of Minor League ball, could really pitch. After opening the season in the bullpen, Fidrych joined the rotation with six consecutive complete games -- two of them going 11 innings -- won eight consecutive starts and didn’t look back. He was the AL starting pitcher in the All-Star Game, tossing two innings before opening the second half of the season three days later with an 11-inning shutout of the A’s. He led the league with 24 complete games and a 2.34 ERA that year. -- Jason Beck More >
TWINS: Tony Oliva, 1964
This was actually a deceptively tough call, but this crown rightfully belongs to Oliva, who became the first rookie to win a batting title in Major League history when he hit .323/.359/.557 as a 25-year-old in 1964. He has since been joined by only Ichiro Suzuki, who replicated the feat in 2001 after several seasons as an established star in Japan. It wasn’t just the average, though, as Oliva also hit 32 homers and an AL-best 43 doubles while stealing 12 bases, showing off the five-tool skill set that helped him lead the AL in hits five times in seven seasons before knee issues led to an early downswing in his career. Oliva also won the batting title in '65 as the Twins won the AL pennant, making him the only player to lead the league in hitting in each of his first two full seasons. -- Do-Hyoung Park More >
WHITE SOX: José Abreu, 2014
Abreu came to the White Sox with 10 highly accomplished seasons played for Cienfuegos of Cuba on his resume, including a .453 average and 1.583 OPS in 2010-11. But there were still Major League questions about the 27-year-old rookie, whose six-year, $68 million deal represented the highest monetary total in franchise history. Abreu answered those questions in his first season by winning the AL Rookie of the Year Award with all 30 first-place votes and finishing fourth in AL MVP voting.
Abreu posted a .317 average, an AL-best .581 slugging percentage and a White Sox single-season rookie record 36 homers. He also knocked out 35 doubles and drove in 107 runs, beginning a highly successful six-year-run now moving into a new three-year-deal as an organization staple. Abreu was hitting .265 as of June 17th during his debut season but hit .351 over his final 88 games and 377 plate appearances. Albert Belle (1997), Minnie Miñoso (1951), Carlos Quentin (2008) and Esteban Loaiza (2003) also deserve strong consideration in this category. -- Scott Merkin More >
ANGELS: Vladimir Guerrero, 2004
The first big move of owner Arte Moreno’s tenure with the Angels was the signing of Guerrero to a five-year deal worth $70 million before the start of the 2004 season. It paid immediate dividends, as Guerrero won AL MVP honors in his first year with the club, hitting .337/.391/.598 with 39 homers, 126 RBIs and a league-leading 124 runs in 156 games. Shohei Ohtani also had an incredible debut season in 2018, becoming a successful two-way player en route to winning AL Rookie of the Year honors, but Guerrero was the MVP and had a bigger impact in his first year with the club. Guerrero also led the Angels to the postseason that year but they ultimately were swept by the Red Sox in the AL Division Series. Guerrero hit just .167 that postseason but homered and had six RBIs in three games, as he had a knack for big hits. He was the club’s second winner of the AL MVP Award and the first since Don Baylor in 1979. -- Rhett Bollinger More >
ASTROS: Roger Clemens, 2004
On the heels of Andy Pettitte signing with his hometown Astros prior to the ‘04 season, Clemens followed him from the Bronx to his home city of Houston, taking baseball excitement to a fever pitch at Minute Maid Park. The 41-year-old Clemens continued to defy Father Time, winning his record seventh Cy Young Award in his 21st season in the big leagues. Clemens went 18-4 with a 2.98 ERA in 33 starts with the Astros and became the fourth pitcher to win the Cy Young Award in two different leagues. He became the oldest pitcher (42) to win a postseason game with a victory in Game 1 of the National League Division Series against the Braves while helping the Astros win their first playoff series in history. He was 9-0 with a 2.08 ERA in his first 12 starts with the Astros and moved into second place on the all-time strikeout list on May 5 when he fanned Raul Mondesi for career strikeout No. 4,137. He also finished the season tied for 10th on the all-time wins list with 328. -- Brian McTaggart More >
ATHLETICS: Frank Thomas, 2006
Released by the White Sox following their 2005 championship season, Thomas was viewed as a player on the decline who was nearing the end of his career. The A’s signed the 38-year-old designated hitter to a one-year, $500,000 deal with incentives for the '06 season and soon found out “The Big Hurt” had plenty left in the tank. Thomas slugged a home run off Randy Johnson on Opening Day at the Coliseum against the Yankees, kicking off a season that would see him finish fourth in AL MVP Award voting as he slashed .270/.381/.545 with 39 homers and 114 RBIs over 137 games. -- Martin Gallegos More >
MARINERS: Ichiro Suzuki, 2001
It’s tough to break in with a bigger bang than Ichiro did in his initial season in the Major Leagues with the Mariners. During Seattle's 116-win season in 2001, the 27-year-old right fielder became the first player in MLB history to win league MVP and Rookie of the Year Award honors, earn Gold Glove and Silver Slugger Awards and start in the All-Star Game all in the same season. After hitting .353 in nine seasons in Japan, there was curiosity over what the slender outfielder could accomplish in MLB after agreeing to a three-year, $14 million contract. He wound up posting a .350/.381/.457 line with 56 stolen bases and 127 runs scored while playing outstanding defense and providing an electric presence atop Seattle’s lineup. Boston’s Fred Lynn (1975) is the only other player to have won MVP and Rookie of the Year Awards in the same season. -- Daniel Kramer More >
RANGERS: Josh Hamilton, 2008
Hamilton spent his rookie season with the Reds in 2007 before being traded to the Rangers. His debut season in Texas was quite the sensation. It wasn’t just the numbers -- 304/.371/.530 with 98 runs scored, 32 home runs and a league-leading 130 RBIs. It was just the whole package from the tremendously gifted athlete who had been resurrected from three-plus years of suspension because of a harrowing journey through drug and alcohol abuse. The highlight didn’t even come during a regular-season game even though he was the AL Player of the Month for April and May. His record-setting performance of 28 home runs in the first round of the Home Run Derby at old Yankee Stadium, including several over 500 feet, remains one of the great moments in All-Star history. -- Kennedi Landry More >
NATIONAL LEAGUE EAST
BRAVES: Greg Maddux, 1993
Maddux exited his April 25 outing with a 3.48 ERA through his first five starts. He had allowed four earned runs in three consecutive starts and had not yet pitched to the expectations of the five-year, $28 million deal he’d signed during the offseason. But he posted a 2.20 ERA over his next 31 starts and won the second of his four consecutive National League Cy Young Awards.
As Maddux produced a 1.52 ERA over his last 13 starts, the Braves erased the 7 1/2-game division deficit they had carried into July 31. His initial season in Atlanta resulted in the Braves winning the third of their 14 consecutive division titles. -- Mark Bowman More >
MARLINS: José Fernández (2013)
When injuries hit the rotation late in Spring Training, the Marlins elected to put their second-ranked prospect on the Opening Day roster. The future ace showed poise on the mound from the get-go, limiting the Mets to one run and striking out eight batters in five innings in his Major League debut at Citi Field.
Fernández's success at a young age garnered him the nickname "Niño." The 20-year-old right-hander made the All-Star team, going 12-6 with a 2.19 ERA and a 0.98 WHIP. Fernández led the Majors with just 5.8 hits per nine innings and produced a 176 ERA+. Of his 28 starts, 20 were quality ones. From June 1 on, he posted a 1.50 ERA and struck out 135 over 120 1/3 innings. Originally projected to begin the season at the Double-A level, a team-imposed innings limit cut his campaign short after 172 2/3 frames. Fernández, who turned 21 on July 31, finished third in NL Cy Young Award voting to established aces Clayton Kershaw and Adam Wainwright. -- Christina De Nicola More >
METS: Dwight Gooden, 1984
What Pete Alonso accomplished in 2019, bashing a Major League rookie record 53 homers, was historic. But it wasn’t quite the most memorable debut season in Mets history. With a nod to Alonso, Mike Piazza, Keith Hernandez and others, no one engineered the same electricity that Gooden did during his 1984 introduction to New York. He won his first career start at age 19, threw his first shutout five weeks later and only improved as the season progressed, going 8-1 with a 1.07 ERA and 105 strikeouts over his final nine starts to win NL Rookie of the Year honors. Although voters snubbed Gooden for the Cy Young Award that went to Rick Sutcliffe, there wasn’t much to quibble with about his 2.60 ERA and league-leading 276 strikeouts. The craziest part? His sophomore season was even better, ending with a unanimous Cy Young Award selection. -- Anthony DiComo More >
NATIONALS: Bryce Harper, 2012
There are players who win the Rookie of the Year Award, those who are named to the All-Star team and those who receive Most Valuable Player Award votes. Then there's Harper, who checked off all three boxes in his debut season.
In 139 games, Harper slashed .270 with an .817 OPS and a 118 OPS+. He also tallied 144 hits, 22 homers, 98 runs, 59 RBIs and 18 stolen bases. Harper was named the NL Rookie of the Month in May and then again in September after wrapping up the final month of the regular season with a 1.043 OPS. -- Jessica Camerato More >
PHILLIES: Steve Carlton, 1972
Phillies general manager John Quinn got crucified for trading Rick Wise to the Cardinals for Carlton in Feb. 1972.
Wise went 17-14 with a 2.88 ERA and made the National League All-Star team in 1971. He not only threw a no-hitter on June 23 in Cincinnati, he homered twice, becoming the face of the franchise in the process. But when Wise and Carlton found themselves in contract disputes with their respective teams, their respective front offices swapped the disgruntled stars. Phillies fans hated the trade.
But Carlton went 27-10 with a 1.97 ERA in 41 starts in his debut season with the Phillies. He pitched 30 complete games, including eight shutouts. He tossed 346 1/3 innings, struck out 310 batters and walked 87. He won the NL Cy Young Award and finished fifth for NL MVP. The rest is history.
-- Todd Zolecki More >
BREWERS: Rollie Fingers, 1981
The statistically correct answer is almost certainly Christian Yelich in 2018, when a second half for the ages made the outfielder the fourth different player in franchise history to win the league’s MVP Award. But Yelich has so dominated these “best” lists of late that we’re deviating down a more sentimental path for Hall of Fame closer Fingers, who was so electric during a strike-shortened 1981 after coming to Milwaukee in a blockbuster trade with the Cardinals that he won both the AL Cy Young Award and became the Brewers’ first league MVP.
Beyond the stellar stats -- 1.04 ERA, 0.87 WHIP -- Fingers represented something bigger for a city that had not tasted postseason baseball since the Milwaukee Braves fell to the Yankees in Game 7 of the 1958 World Series. In that trade for Fingers, Pete Vuckovich and Ted Simmons at the 1980 Winter Meetings, the Brewers acquired the final pieces they needed to make the playoffs for the first time in '81 before winning their first division title a year later and making it to their only World Series to date. -- Adam McCalvy More >
CARDINALS: Albert Pujols, 2001
The Cardinals have had their share of spark plugs who boost a season, but there has been no greater debut season than Pujols as a rookie in 2001.
On his way to unanimously winning the NL Rookie of the Year Award and finishing fourth in NL MVP voting, Pujols hit .329/.403/.610 with 37 homers and 130 RBIs after making the team as a starter out of Spring Training that year. He homered in his first home game and became the first rookie to hit 30 homers since 1997. He set a league rookie record for RBIs and total bases. And he and Ted Williams are two of four rookies to hit better than .300 with more than 100 runs, 100 RBIs and 30 homers. -- Zachary Silver More >
CUBS: Ed Reulbach, 1905
The most famous debut season in Cubs history belongs to Hall of Famer Rogers Hornsby. But when he joined Chicago in 1929 and posted 10.4 WAR (Baseball Reference), he was in his prime and everyone knew what the Cubs were getting. The more fascinating debut goes to Reulbach, who came out of nowhere in 1905.
The 22-year-old righty, who went on to be known as Big Ed, featured a high leg kick (similar to Juan Marichal, per historic accounts) and a sweeping curveball. In his rookie season, Reulbach fashioned a 1.42 ERA, still the lowest ever for a qualified rookie in the Modern Era (since 1900) over 291 2/3 innings. He started 29 games, completing 28 of them along the way to 9.1 WAR. That trails only Irv Young (9.9 in 1905) and Mark Fidrych (9.6 in 1976) for the highest WAR in a pitcher's first season since 1900. Reulbach went on to become an anchor for the Cubs' rotation for four World Series, including the club's triumphs in 1907 and '08. -- Jordan Bastian More >
PIRATES: Honus Wagner, 1900
No surprise here: The best player in Pirates history also made the best first impression. After spending three seasons with the Louisville Colonels, Wagner joined the Pirates in 1900 and hit .381/.434/.573 with 45 doubles, 22 triples, 100 RBIs and 38 stolen bases in 135 games. At 26 years old, he led the NL in batting average, doubles, triples and slugging percentage. Interestingly, the Hall of Fame shortstop didn’t actually play there during his Pittsburgh debut; he spent most of the season in the outfield. -- Adam Berry More >
REDS: Frank Robinson, 1956
Tom Seaver made a marvelous splash in Cincinnati after his trade from the Mets in 1977 (14-3, 2.34 ERA in 20 starts), but Robinson, the only player to appear on this list twice -- burst onto the scene like no other in Reds history. As a 20-year-old rookie in 1956, he hit 38 home runs and led the NL with 122 runs scored -- both served as his career highs until he eclipsed them in 1962. He also batted .290/.379/.558 with an OPS+ of 143, 27 doubles, six triples and 83 RBIs. The season won him the NL Rookie of the Year Award and was the start of a Hall of Fame career that saw him go on to win two MVP Awards and the Triple Crown before a pioneering second career as baseball’s first African American manager. -- Mark Sheldon More >
D-BACKS: Randy Johnson, 1999
Fresh off a 97-loss inaugural season in 1998, the D-backs signed Johnson to a four-year, $52 million deal. The returns were immediate as Johnson put together the first of what would be four straight Cy Young Award-winning seasons. In 1999, he went 17-9 with a Majors-best 2.48 ERA in 35 starts as the D-backs won 100 games and the NL West. Johnson led baseball that year in complete games (12), innings pitched (271 2/3), strikeouts (364) and ERA+ (184). It was a dominant season in every respect and it was only a preview of what would come as he would go 81-27 with a 2.48 ERA, 31 complete games (11 shutouts) and a 187 ERA+ over the four-year contract. -- Steve Gilbert More >
DODGERS: Jackie Robinson, 1947
You will find players that had better stats in their debut season, but you won’t find any player that had a more profound debut season or a greater impact on his sport and society than Robinson’s 1947 Rookie of the Year season. He dealt with unimaginable abuse and threats with courage and grace, played out of position at first base and was on a World Series team that lost to the Yankees in Game 7. Robinson is an icon, even for a franchise that has had 18 Rookies of the Year, an award that now bears Robinson’s name. -- Ken Gurnick
GIANTS: Barry Bonds, 1993
After spending the first seven years of his career with the Pirates, Bonds signed a six-year, $43 million deal with the Giants ahead of the 1993 season and immediately sparked the revitalization of the franchise. His arrival helped turn a 90-loss team into a 103-win team, as he batted .336/.458/.677 with 46 home runs and 123 RBIs to earn the first of five National League MVP Awards in San Francisco. The home run king spent the final 15 seasons of his career with the Giants, hitting .312/.477/.666 with 586 home runs 1,440 RBIs over 1,976 games. -- Maria Guardado More >
PADRES: Kevin Brown, 1998
Brown’s debut season in San Diego was his only season in San Diego. But it was a special one. The veteran right-hander authored arguably the greatest pitching campaign in Padres history, posting a 2.38 ERA with 257 strikeouts and a team-record 11 straight victories at one point. He was the unquestioned ace of the 1998 NL West champs. And Brown upped his game in the postseason, with a 16-K gem in the NLDS and a shutout in the NLCS. Brown’s stay in San Diego would be short-lived. But there haven’t been many better one-season fits in baseball history than Kevin Brown and the ‘98 Padres. -- AJ Cassavell More >
ROCKIES: Trevor Story, 2016
Shortstop mainstay Troy Tulowitzki had been traded in 2015. Tulowitzki’s replacement, José Reyes, was under an MLB suspension. No one knew much about Story, and no one knew what to think when he had a blistering 2016 Spring Training. But Story homered twice off the D-backs’ Zack Greinke in the season-opener, went deep seven times in the first six games and was a key cog for a Rockies team that hung around for most of the summer.
Story had a .272 batting average with a National League rookie shortstop record 27 home runs before having his season cut short by a torn left thumb ligament that occurred on July 30. The Rockies were .500 (52-52) though that date and at least flirted with making big trades to bolster the pitching for a late-season run. The knowledge that the injury put a massive hole in their lineup cooled their pursuit. Without Story, they finished 75-87. -- Thomas Harding More >