Base coaches box, guidance for obstruction call among new rules for '26 season

While the introduction of the Automated Ball-Strike (ABS) Challenge System is the biggest rule change for the 2026 MLB season, two other minor but notable changes in umpire guidance were approved by owners Thursday.

The coaches’ boxes outside the first- and third-base lines will be something other than a suggestion going forward, as umpires will be instructed to ensure base coaches are within the parameters of the box while the pitcher is on the rubber.

Additionally, runners will not be permitted to initiate contact with fielders with the intent to draw an obstruction call.

The base coach positioning guidance is MLB’s answer to an increasingly prevalent trend in which coaches would move out of their designated boxes to get better angles to steal signs by reading pitchers’ grips.

This gamesmanship has caused consternation between clubs and compelled MLB to more proactively monitor base coach positioning during the 2025 World Series, alleviating concerns. Now, that proactive monitoring will occur all season.

If the umpires observe a base coach outside the box between pitches while the pitcher is on the rubber, the coach will receive a warning and be instructed to return to the box. Subsequent violations of the rule can result in an ejection of the coach.

The boxes, as drawn on the field, feature only three sides, with the edge furthest from the field/closest to the dugout undefined. This permits coaches to position themselves further from the field -- but within the parameters of the boxes’ side lines -- if they have safety concerns with a certain batter at the plate.

The baserunner guidance is a response to instances in which runners went out of their way to make contact with fielders who did not have the ball, in order to draw an obstruction call.

The new guidance extends the definition of “unsportsmanlike conduct” to include a runner committing an intentional act of interference unrelated to running the bases while in a rundown or avoiding a tag. If a runner does this, the umpires will rule him out and all other runners will return to the base last touched.