Kiwoom Heroes pitcher Jeon Jun-pyo has emerged as a formidable force in the team’s starting rotation, showcasing a dramatic turnaround from his earlier bullpen struggles. In his first five starts, Jeon has posted an impressive earned run average (ERA) of 2.10, a stark contrast to his previous performance. This transformation is not merely reflected in his ERA; he has demonstrated remarkable stamina, consistently throwing over 90 pitches per game with fastballs reaching up to 157 km/h (97.5 mph).
The 2024 first-round draft pick is rapidly becoming one of the most compelling “starting pitcher reinforcements” for the latter half of the season. Jeon’s recent outings, beginning with the game against the LG Twins on June 28 and extending to the match against the KIA Tigers on July 23, have seen him deliver strong performances over five starts. Across 25.2 innings pitched in these five games, he has yet to record a loss, maintaining a 2.10 ERA, a 1.36 WHIP (walks plus hits per inning pitched), allowing 16 hits, 2 home runs, striking out 14 batters, and issuing 19 walks. He is averaging 5.13 innings per start, and notably, achieved his first career quality start on July 18 against the Lotte Giants by pitching six scoreless innings.
From Bullpen Woes to Starting Stamina
The most striking aspect of Jeon’s resurgence is his ability to maintain velocity and effectiveness even when throwing over 90 pitches. In the game against the LG Twins on June 28, he threw 96 pitches, with his fastball peaking at 157 km/h and averaging 153 km/h. Similarly, during his July 18 start against the Lotte Giants, he utilized 73 fastballs out of 95 total pitches, sustaining speeds over 150 km/h through the sixth inning. This performance makes it hard to believe he is the same pitcher who recorded a 9.35 ERA over 8.2 innings in 10 relief appearances out of the bullpen. His current success suggests that his strong pitching is not just a brief flash of brilliance in short relief stints, but rather genuine stamina that can be sustained throughout the longer innings required of a starting pitcher.
The Foundation of His Success: Preparation and Development
This remarkable transformation is attributed to meticulous preparation and a dedicated development process. Jeon’s journey included a stint in the Futures League, where he received specialized training as a starter. On July 30, he pitched two scoreless innings in the Futures League with a WHIP of 1.00, showcasing his readiness. He was called up on July 28 and effectively fulfilled his starting role against the LG Twins, pitching five innings and allowing two runs.
However, amidst the promising results, certain areas of concern persist. Over his five starts, Jeon has issued 19 walks, averaging 6.66 walks per nine innings (BB/9). His strikeout-to-walk ratio (K/BB) stands at a modest 0.74. In his July 23 start against the KIA Tigers, he managed to limit the damage to two runs over five innings despite issuing five walks without recording a single strikeout. While his current overpowering fastball is effectively suppressing hits, he could become a hittable target if his velocity drops to the 149-151 km/h range.
Key to Sustained Success: Control and Pitch Development
With his above-150 km/h fastball velocity now confirmed, the critical factor for Jeon’s continued success lies in his ability to consistently throw strikes. Reducing his BB/9 to the 4.0 range and developing a reliable breaking ball, such as a slider or a changeup, into a genuine out-pitch will be crucial for him to transition from a mere rotation filler to a key contributor for the Kiwoom Heroes.
While it is too early to definitively label his 2.10 ERA over five starts as a reflection of his fully realized potential, the fact that Jeon, who once struggled to complete even one inning, is now consistently logging five to six innings and maintaining a spot in the starting rotation offers significant hope for the Kiwoom mound. His journey from a struggling reliever to a promising starter highlights the potential for growth and the impact of dedicated development within professional baseball.
