Overview
- MLB’s leaguewide rollout begins Wednesday night at Oracle Park for Yankees–Giants, the first regular-season use after years of minor-league and spring testing.
- The system lets only the batter, pitcher, or catcher issue an immediate helmet‑tap challenge with two per team that are retained on overturns, and MLB plans to use it in the postseason at club parks with some neutral‑site exceptions.
- Hawk‑Eye cameras track each pitch against a two‑dimensional zone over the plate that is 17 inches wide, with the top at 53.5% of a hitter’s measured height and the bottom at 27%.
- Spring trials showed few pitches were challenged and about 53% of calls were overturned, with catchers far more successful than pitchers and many teams preparing to let catchers make most challenge decisions.
- A spring denial of Cavan Biggio’s challenge for moving before tapping highlighted a strict timing rule, and coverage ranged from USA TODAY’s technical explainer to fan‑focused criticism that the ‘immediate’ standard needs clarification.