M.L.B. Approves Technology to Limit Sign Stealing The system, which was officially unveiled on Tuesday, includes a push-button transmitter, worn on the catcher’s glove-side wrist, that sends the desired type of pitch to bone-conduction earpieces inside the caps of the pitcher and any three other players the team designates. I can’t find any details on the encryption scheme.Old-fashioned finger signals and sign stealing may soon become obsolete in Major League Baseball. Teams will begin using electronic devices that transmit signals from catchers to pitchers starting this season.
Tested during spring training, the system is designed to eliminate the temptation for teams to employ illicit means to steal signs, as teams have done throughout baseball history.