The year he turned 20, in September, he made the Asian Baseball Championship team as a Hanyang University freshman, and Korea shared the title with Taiwan and Japan.
The breakthrough yearThe year he turned 22, he went to the Intercontinental Cup and the Asian Championship as the national team’s left-handed ace, and in December the press voted him the 1991 amateur baseball MVP. Yonhap News Agency writes that he made his name in his amateur days as the national team’s best left-handed pitcher.
In 1992, he pitched a complete-game win in the President’s Cup college final. The year he turned 24, he joined the Binggrae Eagles (now Hanwha) as a first-round pick. He had a shoulder injury in his first season and went 2-1 in 6 games. In 1994, he recorded his first save and finished the year with 12 saves. In 1995, he went 4-14 with 18 saves.
In 1996, he was named the regular-season MVP of Korean professional baseball. He went 18-3 with 24 saves, and Yonhap News Agency called the season his second heyday.
In 1999, he closed out Hanwha’s Korean Series title and was named Korean Series MVP. In 2000, he pitched a nine-inning complete-game win over Japan in the Sydney Olympics bronze-medal game, and in December he joined Japan’s Orix. In 2002, he finished second in the Pacific League with a 2.52 ERA at Orix.
In 2005, he joined the New York Mets and made his Major League debut on April 5, Korean time, against Cincinnati. In 2006, he played for the national team at the WBC, then returned to Hanwha and recorded double-digit saves in Korea for the eighth straight year.
In September 2010, he played his retirement game in Korea, and in November he recorded the Australian Baseball League’s first save since its launch for the Sydney Blue Sox.
In 2018, he became manager of Geelong-Korea in the Australian Baseball League. In January 2019, he took the mound himself as manager and threw a scoreless inning. In February 2023, he pitched in three games for Geelong-Korea.
In 2024, he became a baseball commentator for SBS Sports. In 2025, he took over as the inaugural manager of the Shanghai Dragons in China. In February 2026, his team finished as runner-up in the Start of Spring League of China’s city baseball league.
Dae-sung Koo (born in 1969) became known when the press voted him the 1991 amateur baseball MVP on Dec 6, 1991, the year he turned 22, and joined the Binggrae Eagles in 1993, the year he turned 24. In 1996, the year he turned 27, he was named the regular-season MVP of Korean professional baseball.
Ages are by calendar year (the year minus the birth year), birthdays aside.