In football, an signal is when the QB, just before the beginning of the play, changes the called play at the line of scrimmage. Essentially, it's a immediate adjustment! The quarterback might notice something on the https://xem-bng-trc-tip-ko-nh-ci629919.tinyblogging.com/the-is-an-play-call-in-american-football-an-easy-look-86341098