"I was blinded by velocity alone"… Yoon Ye-seong's top velocity of 157 km, a candidate for the No. 3 draft pick
Yoon Ye-seong of Inchang High School blamed his own control despite an unofficial 157 km fastball. He is a candidate for the No. 3 pick in the 2027 KBO rookie draft and will take the mound for the U-18 national team against Taiwan on the 7th.
Translated from Korean with AI assistance. Read the original. Sources and original publication dates are retained.
Three-Line Summary
- Yoon Ye-seong's official top velocity in 2026 is 154 km/h, while his unofficial top is 157 km/h
- Etoday reported that Yoon Ye-seong is being mentioned as a candidate for the No. 3 overall pick in the 2027 KBO rookie draft
- The Korean U-18 national team plays its first group-stage game against Taiwan in Taipei on September 7
"Before the game I promised to hit 157 km, but I was blinded by velocity alone and the game didn't go well." Those were the first words from the high schooler after he came off the mound at Hanwha Life Ballpark in Daejeon on June 8. The top velocity shown on the scoreboard that day was 150.8 km/h, over 1 inning with 1 walk and no runs allowed. In the stands were KBO, MLB and NPB scouts from a total of 24 clubs, all there to watch.
Yoon Ye-seong's top velocity is 157 km, but the official record is 154 km
There are numbers we need to separate first. Star News reports that Yoon Ye-seong's 2026 official game top velocity is 154 km/h, while his top velocity based on his own remarks, the unofficial best, is 157 km/h. The number 157 circulating in search results is not a value entered in the official record sheet.
Yoon Ye-seong, a right-hander at Inchang High School, was born in January 2009 and is 17 years old. He started school a year early, so he is a year younger than his draft classmates. According to the KBSA, his physical profile is 191 cm and 105 kg. He throws 5 pitches: a fastball, curveball, slider, changeup and splitter. A scout from one KBO club evaluated him by saying, "His steady stamina stands out, to the point that he has thrown 150 km/h several times."
13 games, 4 wins and 2 losses, 2.95 ERA, 67 strikeouts
His 2026 high school season record, as published in a Money Today interview, is 13 games, 4 wins and 2 losses, with a 2.95 ERA. Over 58⅓ innings he had 67 strikeouts and 21 walks, with a 1.09 WHIP. His strikeouts per 9 innings come to 10.3 (67÷58⅓×9), more than one per inning. Yet he himself said, "I think of myself as a starting pitcher," putting more weight on pitching longer innings than on velocity.
Not every metric is favorable. The baseball data site 1844 ranked Yoon Ye-seong in its weekly S9 points ranking for third-year high school pitchers, as of the fifth week of August, at 30th. However, this ranking is the site's own tabulation, so it may differ from the official KBSA records. This is where the scouts' eyes and the tabulated metrics diverge.
2027 KBO rookie draft outlook: Yoon Ye-seong in the No. 3 pick range
Etoday cited the outlook of Yu Hyo-sang, editor-in-chief of Yabando, and reported that the No. 1 and No. 2 picks are clear but opinions split starting at No. 3. The name mentioned for that No. 3 spot is Yoon Ye-seong. Multiple outlets reported that Ha Hyeon-seung (18) of Busan High School, the leading candidate for the No. 1 overall pick, turned down a signing bonus offer of 3 million dollars from the New York Yankees in June and chose to stay in the KBO.
| Rank | Name | School | Outlook (as of 2026.08.13, Etoday) |
|---|---|---|---|
| 1 | Ha Hyeon-seung | Busan High School | Leading candidate for No. 1 overall (Kiwoom candidate) |
| 2 | Kim Ji-u | Seoul High School | Leading candidate for No. 2 overall (Doosan candidate) |
| 3 | Yoon Ye-seong | Inchang High School | Candidate for No. 3 overall (KIA candidate) |
| 4 | Lee Ho-min | Gyeongnam High School | Candidate in the No. 4 pick range |
| 5 | Lee Seung-won | Yushin High School | Top-tier if healthy |
| 6 | Park Geun-seo | Seoul Design High School | First-round candidate (left-hander) |
U-18 Asian Championship schedule, starting with the September 7 game against Taiwan
The tournament is held in Taipei, Taiwan, from September 7 to 13. In Group B, Korea faces Taiwan on the 7th, Singapore on the 8th and Thailand on the 9th, in that order. The first game is scheduled for 7:30 p.m. Korea time on the 7th. Money Today reported that the national team arrived in Taiwan on September 5 and began acclimatization training, and that it has only 6 pitchers, including Yoon Ye-seong and Ha Hyeon-seung.
As reported by Yonhap News, the KBSA announced the roster on July 9, and the KBO decided to provide an additional 300 million won in support to strengthen the international competitiveness of the youth national team. The manager is Jeong Yun-jin (55) of Deoksu High School, who has taken the U-18 helm again after 13 years, following 2013.
157 km is unofficial, and 154 km is official. His metric ranking is 30th, yet his draft outlook is No. 3. The draft order will not be decided until the September 21 event. All that has been signaled is that the result of the Taiwan game could shape the course of the Super Round, and that this mound could be the last international showcase for the high school seniors.
Frequently Asked Questions
Q. What is Yoon Ye-seong's top velocity in km?
His official top game velocity in 2026 is 154 km/h. 157 km/h has also been reported, but it is an unofficial figure based on his own remarks and media reports, so it should be treated separately.
Q. How old is Yoon Ye-seong, and what are his height and weight?
He was born in January 2009 and is 17 years old, a year younger than his draft classmates. According to the KBSA, his physical profile is 191 cm and 105 kg.
Q. When is the 2027 KBO rookie draft held?
According to the KBO announcement, it is September 21, 2026. Applications were accepted from July 1 to August 22, and the draft order is not finalized until the event.
Related Official Sites
- KBO Official Website — You can check the rookie draft schedule and official announcements
- KBO 2027 Rookie Draft Application Press Release — The original text of the application period and event date
- Korea Baseball and Softball Association (KBSA) — Official high school baseball records and national team roster
- Hanwha Eagles Official Website — The club that hosts the Hanwha Eagles Cup high school and college all-star game
Lead image · Photo = Pexels (Ayyeee Ayyeee)
Further Reading
· "MLB's top-level fastball"… Dodgers bring in 100-mph Halvorsen
· Lee Jung-hoo ranks 6th in MLB batting average at .302, sits out SF's 16-3 rout after a hit-by-pitch
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