Are MLB players shrinking? Why players are losing inches on their official height due to ABS

The introduction of the automated ball-strike (ABS) system has come with an interesting side effect: MLB players appear to be shrinking. Earlier this month, as teams unveiled players’ official measurements ahead of the season, fans noticed significant differences between players’ heights this year and last year. Several players seemed to lose multiple inches over the one-year span, prompting questions and plenty of jokes.

The reason for the change comes down to ABS: Players’ height measurements were much more rigorous in 2026 than in previous years, as part of the introduction of the ABS challenge system . The system introduces a new strike zone that is based on a percentage of a player’s height, meaning that an exact measurement is more important. How does ABS measurement work?

Though the strike zone has changed over the years, the previous version goes from the middle of a players’ torso down to just below their kneecap. Now, strike zones will be specifically tailored player to player : The top of the zone will sit at 53% of a player’s measured height, while the bottom sits at 27%. In other words, the strike zone will sit around the top half of a player’s bottom half.

In the past, official measurements were more flexible: Per The Athletic , teams used to source players’ heights from their physicals, from last year’s height, or just from the players themselves. “It’s always been like that, from what I remember. I feel like everybody always put an inch or two taller,” Los Angeles Angels catcher Travis d’Arnaud told The Athletic.