The quarter-back calls out a series of numbers and letters called “signals” before the ball is put into play.  These signals will tell his team what the play is to be, whether a run around end, a kick, or a mass play on centre, for example.  The matter of thorough coaching in signals is very important and must be practised by the team until it can tell in an instant just what the play is to be when the play starts.  The centre stoops low and holds the ball in an upright position on the ground between his feet.  The quarter-back is directly behind him with outstretched hands ready to receive it.  After the signal is given the team must be ready to execute the play, but must not by look or motion permit its opponents know what the play is to be.  At a touch or word from the quarter-back, the full-back snaps the ball back and the play starts.

The position of the men on a team is generally as the diagram shows but for various plays other formations are used, provided that they do not violate the rules, which specify just how many men must be in the lineup and how many are permitted behind the line.

The first requirement of signals is to have them simple.  In the heat and stress of a game the players will have but little time to figure out what the play is to be, even though it may all have seemed very simple on paper.

To begin a code of signals each position on the team is given a letter.  The eleven positions will require eleven letters and no two must be alike.  It would be possible of course to simply start with the letter “a” and go to “k,” but this system would be too simple and easily understood by your opponents.  A better way is to take a word easily remembered in which no letter occurs twice, such as “B-l-a-c-k-h-o-r-s-e-x” or any other combination.  “Buy and trade” “importance,” “formidable,” and many others are used.  The same principle is used by tradesmen in putting private price marks on their goods.

Take the words “buy and trade” for example.  Their positions right and left end, abbreviated (r.e. and l.e.), right and left tackle (r.t. and l.t.), right and left guard (r.g. and l.g.), centre (c.), quarter-back (q.), right and left half-backs (r.h. and l.h.), and full-back (f.b.), would be assigned letters as follows: 

      l.e. l.t. l.g. c. r.g. r.t. r.e. q. l.h. f.b. r.h.
      B U Y A N D T R A D E

The letters denote not only players but holes in the line, as the spaces between the players are called.  The quarter-back always adds to his signal a number of other letters or figures which have no meaning, simply to confuse the opposing players.  For example the signal given is “24-E-N-72-X.”  The figures 24 and 72 mean nothing, nor does the “X.”  The signal says “E will take the ball and go through N,” or right half-back through right guard.  Any number of other plays can be denoted by letters or numbers, for example all punts by figures which are a multiple of ten, as 10-20, 150-300, and so on.