The Korea Baseball Organization (KBO) announced that starting August 19, it will officially implement video review for check swing calls at all KBO League stadiums.

This new rule follows the precedent set by the Futures League and defines a swing strike as occurring when the tip of the batter’s bat crosses a parallel line in front of home plate toward the pitcher. If the bat angle exceeds 90 degrees, it is considered a swing; if it is 90 degrees or less, it is deemed a no-swing. The position of the bat handle, rotation of the batter’s body, and other factors are not considered. Attempts at bunting are also excluded from video review.

Each team is permitted two video challenges per game, separate from existing review opportunities. If a call is overturned, the opportunity is retained. An additional challenge is granted in extra innings. Only team managers can request a review—batting teams may challenge a swing call, while fielding teams may contest a no-swing call. Requests must be made within 30 seconds following an umpire's decision or within 10 seconds after an inning ends. Once the next pitch is thrown, challenges can no longer be accepted.

If either of the two dedicated KBO cameras installed at each stadium fails to operate, video review for check swings will not be conducted in that game. All reviews will be based solely on KBO’s official broadcast footage.

In situations where runner placement must be adjusted, the crew chief will consult with the video review center before making a final call, adhering to existing review protocols. Should a check swing overturn a 'ball' call when the catcher fails to catch the third strike, the batter will be automatically out without needing a separate tag or throw, matching the current rules of US minor leagues. If a dropped third strike enters the dead ball zone in what would have been a dropped third strike situation, all runners and the batter-runner advance one base. Additionally, if an initial call is deemed to have impacted the flow of play, the umpiring crew has discretion, with input from the review center, to reposition runners accordingly. However, bases not actually touched prior to reversal will not be awarded, except in specific cases where a following runner occupies a base.

The check swing video review system will also be in effect during the postseason.

Prior to launching the new initiative, the KBO conducted internal analysis of recent game cases and briefed both managers and players on detailed procedures to ensure smooth operation. Umpires and video review center personnel also received specialized training and held dedicated meetings to minimize confusion and ensure efficient application on the field.

A KBO official expressed optimism about the change, stating, “We expect the introduction of check swing video review to significantly enhance the accuracy and fairness of umpiring decisions,” and anticipated increased satisfaction among players, officials, and fans alike.

Note “This article was translated from the original Korean version using AI assistance, and subsequently edited by a native-speaking journalist.”

Photo=Yonhap News, Korea Baseball Organization