MLB 對於全壘打牆的 official rule (a) Any Playing Field constructed by a professional club after June 1, 1958, shall provide a minimum distance of 325 feet from home base to the nearest fence, stand or other obstruction on the right and left field foul lines, and a minimum distance of 400 feet to the center field fence. (b) No existing playing field shall be remodeled after June 1, 1958, in such manner as to reduce the distance from home base to the foul poles and to the center field fence below the minimum specified in paragraph (a) above.
但很多新球場並沒有照這個規定, 例如新Yankee Stadium, AT&T Park, Petco Park 還有一條規定 "No part of the uniform shall include a pattern that imitates or suggests the shape of a baseball" 這個規定Milwaukee Brewers 1978-1993之前有犯過, 但還是可以比賽