Seoul: The South Korean baseball league, Korea Baseball Organization (KBO), has announced several rule changes for the 2025 season, including the introduction of a pitch clock and adjustments to the automated ball-strike (ABS) system. The changes aim to enhance game efficiency and international competitiveness.
According to Yonhap News Agency, the KBO will implement a pitch clock starting in the 2025 regular season. Pitchers will be required to begin their delivery within 20 seconds when the bases are empty and 25 seconds with runners on base. This contrasts with Major League Baseball (MLB), where pitchers have 15 seconds with no runners and 18 seconds with runners on. Although the KBO intended to introduce the pitch clock earlier, opposition from teams delayed its enforcement. The league, however, monitored violations without imposing penalties.
The new regulations will also impose a 33-second limit for batters between plate appearances, allowing only two timeouts per appearance. These modifications were d
ecided during an executive committee meeting involving general managers from the league’s 10 clubs. Unlike MLB, the KBO will not restrict the number of disengagements for pitchers, allowing more flexibility and a focus on fan experience by reducing unnecessary delays.
The KBO has also revised the ABS strike zone, which was first introduced in 2024. The strike zone’s top will be adjusted to 55.75 percent of a hitter’s height, and the bottom to 27.04 percent, effectively lowering the zone without altering its overall size. Additionally, the KBO plans to test a check swing challenge system in its minor league, the Futures League, which could be introduced to the major league by 2026.
The league has begun installing cameras at select stadiums since August to assess the feasibility of the check swing challenge system, similar to trials conducted in the Arizona Fall League in the United States. This system allows teams to contest on-field check swing calls by evaluating if the bat’s head crosses a designated thre
shold.
In response to MLB’s recent adjustments, the KBO has modified the “three-foot rule,” expanding the runner’s lane between home plate and first base. Under the new rule, batters will be considered compliant as long as both feet remain on the dirt, eliminating the previous requirement to run in foul territory.