Overview
- For 2026, MLB has implemented the Automated Ball-Strike challenge system using a 2D zone defined as 17 inches wide and vertically from 27% to 53.5% of each player’s height.
- Players were measured barefoot and hatless with heels together, knees exposed, backs against a wall, and no slouching, with measurements taken between 10 a.m. and noon and repeated at least twice with a third check if needed.
- Updated roster bios show numerous height reductions, including Gavin Lux from 6-foot-2 to 5-foot-11, Bo Naylor from 6-foot to 5-foot-9, Connor Wong from 6-foot-1 to 5-foot-11, Tucker Barnhart from 5-foot-11 to 5-foot-8, and Alex Bregman now listed at 5-foot-10.
- MLB will station measuring devices at every ballpark during the season, with a member of the home team’s medical staff designated as the official measurer for call-ups.
- Spring games with ABS challenges produced multiple overturned calls and visible learning-curve moments for umpires, reinforcing how the player-specific zones will influence reviews and on-field strategy.