Why MLB umpires check pitchers' hands after the inning is over?

MLB umpires face a demanding job each game, with responsibilities extending beyond rule enforcement. A key part of their role is monitoring pitchers closely to ensure no rules are being broken, a task that’s become more complex as pitchers develop new techniques to outsmart batters.

Umpires inspect pitchers’ hands for illegal substances that could give an unfair advantage, often checking after an inning ends. Starting in 2021, MLB began mandating random checks on pitchers’ hands, hats, gloves, and belts to spot any foreign substances. The move followed revelations that some pitchers were using “Spider Tack,” a sticky resin-based substance, to improve grip. Since then, inspections have intensified, even including the inside of pitchers’ pants in extreme cases.

Some of the most common illegal substances used by pitchers include pine tar and sunscreen, both of which increase grip on the ball. MLB’s official stance emphasizes a “uniform standard for the consistent application of the rules,” which includes routine checks on all pitchers, regardless of whether an opposing manager raises concerns.

Consequences of Foreign Substance Violations

If an umpire finds evidence of a foreign substance on a pitcher’s hand, the pitcher is immediately ejected and faces a 10-game suspension. MLB has taken a firm stance against foreign substances to ensure a fair, competitive playing field, believing that harsh penalties will discourage the use of banned substances.

Challenges Umpires Face in Detecting Foreign Substances

One of the greatest challenges MLB umpires face is that illegal substances are often difficult to detect. Pitchers have become more sophisticated, developing advanced methods for concealing and applying substances. This evolution in pitcher tactics keeps umpires on their toes, as they work to enforce rules that protect the integrity of the game.

In addition to checking for illegal substances, umpires also stay vigilant about specific pitching regulations, such as the balk rule and rules against illegal pitches, all while keeping an eye out for anything unusual in a pitcher’s motions.