︎shave rule
n.— «Add the fact that curveballs aren’t allowed, with a few exceptions for more developed pitchers, who fit what is called the shave rule, meaning that a youngster is generally physically developed enough to safely throw curves when they begin to shave, and there’s a declined risk of the injury.» —“Ted Williams Baseball League finds way around Little League Elbow” by WIlliam Wassersug Wicked Local (Cohasset, Massachusetts) Mar. 27, 2009. (source: Double-Tongued Dictionary)
Further reading
In 1971, when a new public library opened in Troy, Michigan, famous authors and artists were invited to write letters to the city’s youngest readers, extolling the many benefits of libraries. One of the loveliest was from E.B. White, author of...