Sender, Receiver, Feedback

Brett Farve was a quarterback in the NFL.  He was known to be a great quarterback, but he was also known for throwing quite a few interceptions.  To be a good quarterback, you also need good receivers.  If you don't communicate well with your wide receiver, the quarterback, who is the sender of the ball, will not complete the pass to him.

For example, the quarterback tells the other team members what play is being called.  Everyone knows where they need to be to make the play successful.  However, if the other team can read the play, by watching the quarterback's facial expressions and hand motions, the quarterback may call an audible for a different play.  If the receiver is confused and doesn't follow the new play, the defense may have an opportunity to intercept the ball and run it back for a touchdown for their team.

In the NFL, plays are being made based on hand motions, yelling, both verbal and non-verbal communications.  Since each play happens so quickly, everyone must pay attention to the feedback being given.