In a recent memo sent to all 30 teams, Major League Baseball (MLB) provided insights into the future of the automated balls and strikes system (ABS) in the major leagues. The memo stated that starting from June 25, all Triple-A games will transition to a challenge system, which had been tested alongside a fully automated strike zone since the 2023 season.

The announcement indicates that MLB is inclining towards implementing a challenge system in the majors. However, specific details such as the arrival date, the technology to be used, and the exact mechanics of the system are yet to be finalized.

MLB has been conducting trials of both options in Triple-A since last season. The league's research revealed a strong preference for a challenge system with a set number of challenges per game, as opposed to the current process of umpires making calls without technology or a fully automated strike zone.

MLB Commissioner Rob Manfred expressed that there is overwhelming support for the challenge system over complete ABS from players and fans alike. According to MLB's findings, 61% of team personnel and fans favor a challenge system, while 28% prefer sticking with the current no-technology system, and only 11% want a fully automated strike zone.

To determine the number of challenges each team will receive per game in the future challenge system, MLB will observe the outcomes during Triple-A games. For instance, in the Pacific Coast League, each team will be granted three challenges, while in the International League, each team will have two challenges.

Taking fan feedback into consideration, MLB officials believe that fewer challenges would be preferable to maintain the pace of the game. Limiting the number of challenges might encourage teams to exercise more caution in their usage.

The earliest possible implementation of the challenge system in the majors is estimated to be in 2026. MLB aims to perfect the technology and ensure that the implementation is the right step for the game before introducing it at the highest level. This timeline is consistent with previous adjustments made in the minors, such as the pitch clock and shift ban.

The main technological hurdle to overcome is defining the top and bottom of the strike zone for each player. MLB has two options at hand: a height-based zone or a stance-based zone. The height-based zone would involve measuring players before each season and setting their strike zones accordingly. The stance-based zone would rely on camera readings of a player's knees and hips to determine the strike zone based on the rolling median of the last 50 pitches seen by the batter.

MLB acknowledges the challenges in implementing a stance-based zone, as it would differ more significantly from the current human-umpire zone compared to the height-based approach. Additionally, technical issues such as capturing the belt of players whose jerseys hang over their stomachs need to be resolved before the technology is ready for implementation in the major leagues.

Contrary to expectations, the league's research indicates that the high number of strikeouts in MLB is not heavily influenced by pitches on the edges of the strike zone. The study suggests that the prevalence of strikeouts is likely due to higher velocities, rather than the size of the zone itself. Therefore, reducing the size of the strike zone may not significantly impact offensive output.

One potential benefit of implementing the automated zone in the majors would be the reduced learning curve for younger players. Many rookies who have transitioned from Triple-A to the majors have struggled with adjusting to the human umpire strike zone after experiencing an automated zone in the minors. The challenge system, in which only egregious missed calls are reviewed, mitigates the impact of slight differences in the strike zone.

As MLB moves closer to implementing a challenge system for ABS, it is evident that the league is committed to getting the system right before making significant changes to the game. The focus is not only on perfecting the technology but also on ensuring that the implementation enhances the sport without compromising its integrity.