text: It goes back to nearly the beginning of football when the first quartbacks where created to take the snap of the ball from the center (or ball snapper).  The word set was to tell all the players on the field to get set (get in place) because the play (the snapping of the ball) was soon to happen.  However, the history of "hut" is more obsecure.  It is know that for many years prior to the adoption of the word "hut" into the use of army drill sargents by saying "hut, 2, 3, 4" so it is possible it was incorporated into football because it was easier to hear than a number while maintaining discipline among the players on the field.  I hope this helps.