In baseball, sign stealing is the act of observing the signs being signaled by the opposing catcher to the pitcher or a coach, and the subsequent relaying of those signals to members of one's own team
Catcher James McCann (in white uniform) of the Detroit Tigers using his right hand (obscured) to give signs to his pitcher, in a 2015 game against the Minnesota Twins.
Catcher Malachi Kittridge of the Boston Beaneaters demonstrating how he gives signs, circa 1903.
Joe Nossek, who served as an MLB coach for 28 seasons, was considered a "sign-stealing guru".
PitchCom is a wireless communication system used in baseball that lets a player request pitches without using visible signals. Major League Baseball approved the use of PitchCom before the start of th
Sign stealing
…when runners were on second base to try and negate the risk of sign-stealing. Prior to the 2022 MLB season, the league announced that teams could use PitchCom, a wireless communication system that allows the catcher to request pitches without using visible signals. Many players and coaches throughout baseball…
Francisco Álvarez of the New York Mets with a PitchCom extension tube/earpiece in his ear