One of the most exciting parts of Major League Baseball is when an up-and-coming young player takes the big leagues by storm.
The game today is full of bright young talents. Many of MLB's current superstars ascended to the pinnacle of the sport at a young age. And some of baseball's all-time greats did the same. Some got their start even earlier than most ... even before turning 20 years old. MLB.com looks back at some of the most impressive teen campaigns -- from Bob Feller to Dwight Gooden to Felix Hernandez, from Mickey Mantle to Ken Griffey Jr. to Bryce Harper to Juan Soto.
Here are 20 of the best seasons ever by teenagers -- 10 hitters and 10 pitchers. The players are listed in order of their Wins Above Replacement for the season, using Baseball Reference's version.
Bryce Harper, Nationals
Year: 2012. Age: 19
Wins Above Replacement: 5.2
Video: Must C Classic: Harper hits first postseason homer
Even when he was in high school, Harper was being touted as the next huge MLB superstar. He's become exactly that. It all started with his rookie campaign with the Nationals in 2012, when he hit .270/.340/.477 over 139 games with 22 home runs, 59 RBIs and 18 stolen bases. He finished the season with a 5.2 WAR, the most in the modern era for a teenage position player, and his 57 extra-base hits are the most in a teenage season in the modern era. Bryce was named a National League All-Star and the Rookie of the Year, he hit his first postseason home run that year -- and he's gone on to even bigger and better things.
Video: MLB.com looks over Harper's award-winning season
Mel Ott, Giants
Year: 1928. Age: 19
Ott's Hall of Fame career started in 1926 at age 17, but his breakout effort came two years later at the ripe young age of 19. In 124 games for the New York Giants, Ott batted .322/.397/.524 with 18 home runs and 77 RBIs. Ott emerged as the Giants' primary right fielder and a force in the heart of their batting order, primarily hitting third or cleanup for a 93-61 Giants club that finished as the runners-up to the Cardinals in the NL.
Ken Griffey Jr., Mariners
Year: 1989. Age: 19
Video: CWS@SEA: Ken Griffey Jr. hits his first MLB home run
The Kid was, well, a kid when he introduced the baseball world to one of the sweetest swings of all time, ripping a double in his first Major League at-bat. Griffey hit 16 home runs, drove in 61 runs and stole 16 bases for the Mariners in his debut 1989 season, hitting .264/.329/.420 in his 127 games. The Seattle icon and Hall of Famer finished third in the American League Rookie of the Year voting, but his true emergence as a star would begin the following season.
Edgar Renteria, Marlins
Year: 1996. Age: 19
The Marlins were only in their fourth season as a Major League franchise when Renteria made his big league debut as a 19-year-old in May of 1996. The young shortstop would become a key part of the Marlins' rapid ascendance to shock-the-world World Series champs in 1997. Renteria finished second in NL Rookie of the Year voting in 1996. He hit .309/.358/.399 with five homers, 31 RBIs and 16 steals in 106 games while playing a premium defensive position. The next year, he would line the walk-off hit in Game 7 of the World Series.
Video: '97 WS, Gm 7: Renteria wins it for Fish
Juan Soto, Nationals
Year: 2018. Age: 19
Soto burst onto the scene as the youngest player in MLB in 2018. Soto skyrocketed through the Nationals' system, beginning the 2018 season at Class A and mashing his way to three promotions in a month, culminating with his arrival in Washington. Once he got to the big leagues, Soto immediately slugged himself into the National League Rookie of the Year race. Soto hit .292/.406/.517 with 22 homers and 70 RBIs in his 116 games, finishing as runner-up for Rookie of the Year to Ronald Acuna Jr.
Ty Cobb, Tigers
Year: 1906. Age: 19
The baseball legend showed the first inklings of the Hall of Fame career that was to come as a 19-year-old in 1906. Cobb had debuted with the Tigers the year before and played just 41 games; as an MLB sophomore, he upped that total to 98 games and hit .316/.355/.394 with a home run (it was the dead-ball era, after all), 41 RBIs and 23 stolen bases. The next year, he was a superstar, winning his first batting title, leading the Majors with 212 hits and 119 RBIs and leading the AL with 53 steals while helping turn Detroit from a sixth-place team into pennant-winners.
Buddy Lewis, Senators
Year: 1936. Age: 19
Lewis turned in a more-than-solid 1936 campaign for the Senators at age 19. The third baseman provided stability out of the No. 2 spot in the order for Washington all season, hitting .291/.347/.399 with six home runs and 67 RBIs in 143 games. His 175 hits in 1936 are the highest single-season total for a teenager in the modern era, as are his 13 triples and 100 runs scored. Lewis would go on to become a two-time All-Star for the Senators, first in 1938, and then again in 1947 after returning from military service in World War II.
Travis Jackson, Giants
Year: 1923. Age: 19
Jackson, who was elected to the Hall of Fame by the Veterans Committee in 1982, was a defensive star at shortstop for the Giants teams of the 1920s and '30s. His first extended stint in the big leagues came at age 19 in 1923, when he played 96 games, hit .275/.321/.391 with four homers and 37 RBIs, and most importantly excelled in the field at short and third base. He wasn't yet the team's anchor in the middle infield, but he was a contributor to the New York club that won the NL pennant.
Cesar Cedeno, Astros
Year: 1970. Age: 19
One of the earliest great Dominican-born players after Felipe Alou and Juan Marichal, the four-time All-Star and five-time Gold Glove center fielder got his start as a teenager for the Astros in 1970. He made his MLB debut in June and was impressive from the start. Cedeno played 90 games for Houston, hitting .310/.340/.451 with seven home runs, 42 RBIs and 17 stolen bases. He finished fourth in NL Rookie of the Year voting, and starting the next season, became a regular in the heart of the Astros' lineup.
Manny Machado, Orioles
Year: 2012. Age: 19
Video: KC@BAL: Machado blasts the first homer of his career
Harper wasn't the only superstar to debut as a 19-year-old in 2012. Over in the American League, Machado was getting his first taste of Major League action in Baltimore. He wasn't the offensive force he is now out of the gate -- Machado hit .262/.294/.445 with seven homers and 26 RBIs in 51 games as a rookie -- but he was a game-changer defensively at third base right from the start. He's since made three All-Star teams, won two Gold Gloves and finished in the top five of AL MVP voting twice.
Tony Conigliaro, Red Sox
Year: 1964. Age: 19
Video: CWS@BOS: Conigliaro homers in first Fenway at-bat
Conigliaro has one of baseball's sadder stories, as his promising career was derailed after he suffered a serious eye injury when he was hit in the face by a pitch on Aug. 18, 1967. In his first few seasons, the Red Sox outfielder looked like a budding star. He hit his first Major League home run in his first at-bat at Fenway Park, and as a rookie in 1964, he hit .290/.354/.530 with 24 home runs and 52 RBIs in 111 games. Those 24 homers are the modern-era record for a teenager in a season. The next year, as a 20-year-old, Conigliaro hit 32 homers to lead the league, making him the youngest home run champion in AL history.
Mickey Mantle, Yankees
Year: 1951. Age: 19
Video: BAL@NYY: Mickey Mantle hits his 500th home run
Mantle started his legendary Yankees career as a 19-year-old in 1951. He made his first start on Opening Day, batting third for New York against the Red Sox, and recorded his first hit with an RBI single. He was sent to the Minors after a slump, but made it back to the big leagues and finished the year with a .267/.349/.443 slash line, adding 13 home runs and 65 RBIs. He got limited action in the World Series -- which the Yankees won, beating the Giants -- but of course, The Mick went on to plenty of success in his Hall of Fame career, one of the greatest of all time.
Gary Nolan, Reds
Year: 1967. Age: 19
A Reds Hall of Famer, Nolan had a superb first big league season, and it was all the more remarkable considering his young age. When he made his MLB debut on April 15, 1967 -- which he won -- he hadn't even turned 19 yet. The right-hander finished his rookie year 14-8 with a 2.58 ERA in 33 games, striking out 206 batters in 226 2/3 innings and throwing five shutouts. He ranked fourth in the NL in ERA and strikeouts, and finished third in Rookie of the Year voting (Tom Seaver won). Arm trouble would shorten Nolan's career, but he was an All-Star in 1972, and won the clinching Game 4 of the 1976 World Series against the Yankees.
Dwight Gooden, Mets
Year: 1984. Age: 19
Video: 1984 ASG: Dwight Gooden strikes out the side
Doc's legendary 1985 campaign as a 20-year-old is one of the most dominant seasons in MLB history, and he was the ace of the 1986 World Series champion Mets -- but before all that, he burst onto the scene with a brilliant rookie year at age 19 in 1984. Gooden went 17-9 with a 2.60 ERA and a Major League-best 276 strikeouts, pitching 218 innings over 31 starts. He was an All-Star (and struck out the side in his appearance in the Midsummer Classic), a runaway NL Rookie of the Year and the runner-up for the Cy Young (to Rick Sutcliffe). His 276 strikeouts are a modern-era rookie record to this day. No wonder they called him Dr. K.
Bob Feller, Indians
Year: 1938. Age: 19
Feller actually played three seasons as a teenager, beginning his Major League career as a 17-year-old in 1936. But his age-19 season was the best of the three. In fact, it was his breakout year. The Hall of Famer went 17-11 with a 4.08 ERA in 39 games (36 starts) for the Indians, throwing 277 2/3 innings -- a modern-era record for a teenager -- and striking out a Major League-leading 240 batters. He made his first career All-Star team.
Chief Bender, Athletics
Year: 1903. Age: 19
Another Hall of Famer on the list, Bender made his Major League debut just before his 19th birthday in 1903. He went 17-14 with a 3.07 ERA and 127 strikeouts for the Philadelphia Athletics as a rookie, throwing 270 innings over 36 games, 33 of them starts. Bender was the third pitcher in the A's rotation that year, behind a pair of fellow Hall of Famers, Eddie Plank and Rube Waddell. Bender would eventually become the team's ace and help the A's win three World Series during his career.
Rube Bressler, Athletics
Year: 1914. Age: 19
Bressler is something of an interesting figure. He started his career as a pitcher in the later years of the dead-ball era (pre-1920), but converted into an outfielder and first baseman during the live-ball era. As a 19-year-old in his first season, the young left-hander went 10-4 with a sparkling 1.77 ERA and 96 strikeouts in 147 2/3 innings. He was mainly used as a reliever, pitching 29 games but starting just 10. It would end up his best season on the mound.
Wally Bunker, Orioles
Year: 1964. Age: 19
After a one game cup of coffee as an 18-year-old in 1963, Bunker jumped into the Baltimore rotation in 1964 and had himself a great year. He led the American League with a .792 winning percentage, going 19-5 in his 29 starts, with an excellent 2.69 ERA in 214 innings. He was the first teenage pitcher in the divisional era to eclipse the 200-inning mark in a season. Bunker pitched 12 complete games for the O's, including one shutout, and was the AL Rookie of the Year runner-up to Tony Oliva. He even received some MVP votes.
Bob Feller, Indians
Year: 1937. Age: 18
Here's another one of Feller's teenage years -- he was good enough as a teenager to qualify for this list twice. Feller's age-19 season in 1938 was his breakout, but he had a solid year in 1937, too, even though he was only 18 years old. Feller pitched 26 total games and made 19 starts for the Tribe that season, going 9-7 with a 3.39 ERA and 150 strikeouts in 148 2/3 innings.
Larry Dierker, Astros
Year: 1966. Age: 19
Long before he was the NL Manager of the Year for the 1998 Astros, Dierker was toeing the rubber for Houston as a teenager in the 1960s. His MLB debut was on his 18th birthday in 1964, but his best teenage season came two years after that in his age-19 season in 1966. That was his first year as a full-time starter -- Dierker made 28 starts for the Astros, going 10-8 with a 3.18 ERA and 108 strikeouts in 187 innings.
Smoky Joe Wood, Red Sox
Year: 1909. Age: 19
The dead-ball-era Red Sox hurler got his first extended stint in the Major Leagues as a 19-year-old in 1909, when he pitched in 24 games for Boston, making 19 starts. Wood went 11-7 with a 2.18 ERA that season, throwing four shutouts and striking out 88 batters in 160 2/3 innings. His best season would come a few years later in 1912, when he had a Major League-best 34-5 record, throwing 35 complete games and 10 shutouts as he led the Red Sox to a World Series championship over the Giants.
Felix Hernandez, Mariners
Year: 2005. Age: 19
Video: SEA@DET: Felix makes his MLB debut, fanning four
After being named the Mariners' Minor League Pitcher of the Year in 2004 and pitching in the All-Star Futures Game, Hernandez earned his first Major League callup in August of 2005. When he made his MLB debut on Aug. 4 at 19 years, 118 days old, he became the youngest pitcher to appear in a big league game since Jose Rijo in 1984. King Felix made 12 starts down the stretch as a rookie, showing flashes of the talent that would make him one of the top pitchers in the American League in the seasons to come. Hernandez had a 2.67 ERA in those first 12 career starts, and he struck out 77 batters in 84 1/3 innings.
Walter Johnson, Senators
Year: 1907. Age: 19
The Big Train got his start in the big leagues a few months shy of his 20th birthday. Over the next two decades, he would build the Hall of Fame legacy that made him a baseball legend. But as a 19-year-old rookie, Johnson pitched only 14 games (12 of them starts) for the 1907 Senators. He went 5-9, but his record belied how well he pitched. Johnson had a 1.88 ERA in those 14 games, which included the first two of his all-time record 110 shutouts, and he recorded 71 strikeouts in his 110 1/3 innings on the mound.
David Adler is a reporter for MLB.com based in New York. Follow him on Twitter at @_dadler.