Stepping within the plane of the plate

Pitchers are required to NOT step outside of the 24-inch width of the pitchers plate during their delivery. We have seen more pitchers violating this rule by stepping outside of the plane of the pitchers plate. This allows the pitchers to gain an unfair advantage, adding to their crossfire effect, a curveball or a screwball.

This is an illegal act and should be called by the plate umpire. It's an easy call and takes nothing away from your ability to call strikes.

In NCAA, the fields are marked with a pitcher's box to help establish and maintain legal deliveries by pitchers.

Video courtesy NFHS.