MLB’s introduction of the Automated Ball-Strike (ABS) Challenge System in 2026 has led to an unexpected side effect: A league-wide case of apparent shrinkage.
To ensure strike zones are calibrated with pinpoint accuracy—down to the millimeter—MLB requires precise height measurements for every player. These are conducted barefoot, hatless, with knees exposed, heels together, and back flat against a wall, all between 10:00 a.m. and noon to account for natural daily height fluctuations from spinal compression.
The strike zone is now personalized, with its top at 53.5 percent of a player’s height and bottom at 27 percent. This precision has prompted roster updates that reveal many players listed shorter than in previous seasons, as old figures often included generous rounding or optimistic self-reporting.
Standout cases include infielder Gavin Lux, who dropped from 6-foot-2 to 5-foot-11, a three-inch “loss” that has sparked plenty of clubhouse ribbing.
Other notable adjustments feature Bo Naylor from 6-foot to 5-foot-9, Connor Wong down two inches to 5-foot-11, and several others trimmed by an inch or more. While no actual growth plates closed overnight, the strict protocol has exposed the truth behind those longstanding height boasts.
For hitters, a slightly lower listed height might tighten the upper zone, offering a subtle edge in challenges. Pitchers, meanwhile, adapt to more exact boundaries. In the era of robot-assisted umps, it turns out the biggest shrink ray in baseball is simply a measuring stick—and honesty.
