19 Nineteen appears to be the age when the precocious baseball player breaks out. Bryce Harper of the Washington Nationals hit 22 home runs in 2012, two short of the teenage record set in 1964 by Tony Conigliaro of the Boston Red Sox. Conigliaro was badly injured by being hit by a pitch in 1967; he finished with just 166 career homers. Mel Ott might have had the best season by a teenager, in 1928 for the New York Giants. He hit .322 with 18 home runs on his way to a Hall of Fame career.
On the pitching side, Tampa's Dwight Gooden (pictured) was 17-9 for the New York Mets in 1984, and Bob Feller was 17-11 for the Cleveland Indians in 1938; both led the league in strikeouts. Less well remembered is the amazing season of Wally Bunker in 1964 for the Baltimore Orioles: He was 19-5 with a 2.69 ERA. Like many young pitchers, he was plagued by arm trouble and was out of the majors at 26 with 60 career wins.
After becoming the world's No. 1 player at 17, Lydia Ko became the youngest ever major winner on the LPGA Tour at 18, when she won the Evian Championships in France last fall. She added another major in April just short of her 19th birthday.
Boris Becker's win at Wimbledon at 17 in 1985 is well-remembered, but Michael Chang (pictured) was more than 100 days younger when he triumphed at the French Open in 1989. Becker won five more Grand Slam titles; Chang none.
Young Tom Morris claimed the British Open in 1868 at age 17, and to this day is still the youngest major winner in men's golf. He won three more Opens, but died from heart problems at 24.
Wilfred Benitez had his first professional fight at 15. At 17, he won the WBC light-welterweight championship, beating 30-year-old Antonio Cervantes.
Freddy Adu has been a disappointment after signing as a pro with D.C. United at age 14. After many stops, he is now a member of the Tampa Bay Rowdies of the NASL at 26. But he still holds the record for the youngest U.S. national team appearance, at 16, when he came on as a substitute in a friendly against Canada in 2006. (Adu has not played in a match for the Rowdies this season despite being eligible.)
Martina Hingis became the youngest Grand Slam event winner when she won the 1997 Australian Open at 15. She won four more majors over the next three years, but no more after age 18.
Joe Nuxhall was the youngest ever to play major league baseball, pitching briefly in a game for the Cincinnati Reds when he was 15 during the wartime player shortages of 1944. It took him eight years to get back to the big leagues, but he eventually pitched respectably till he was 37.
Dominique Moceanu is the youngest of the many young American gymnasts to win a gold medal at the Olympics, winning the team event with the United States in 1996 at age 14. That record will not be broken under the current rules, which require a gymnast to turn 16 in the calendar year of the Olympics.
The youngest American gold medalist, and the youngest from any nation in the Summer Games, is Marjorie Gestring, who won the springboard diving at 13 in 1936 in Berlin. The New York Times described her as "a blond, small, and very much tanned child from sunny California." She would have been favored for another gold in 1940, but those games were canceled because of World War II.
Gestring is edged out by Kim Yun-Mi, 185 days younger, who was a member of the gold-medal-winning short-track speedskating relay team of South Korea in 1994.
After the Dutch rowing pair at the 1900 Olympics in Paris, Roelof Klein and François Brandt, lost their preliminary heat, they suspected the reason was that their coxswain was a full-grown man, rather than a child, as the French were using. They recruited a French boy for the final and won. The boy's name and age are unknown (estimates range from 7 to 12), but he is in all probability the youngest gold medalist ever.
Contributing: tbt* staff