I was just reviewing some materials on the hidden ball play that Carlisle ran successfully against Harvard in 1903 and learned that getting the play off correctly was more complicated than it seemed. For starters, the kickoff had to be deep enough to give the players time to assemble around the person who received the kick, James Johnson in this case. The Harvard kicker put his first kick out of bounds and had to rekick. There must not have been much of a penalty for that in those days because he was able to put the second kick on the goal line.
Johnson’s teammates had to line up precisely to make the other team think they were forming a wedge to block for Johnson. Room for Johnson to stand next to Dillon was essential to making the play work. It was (and probably still is) illegal to hand or pass the ball forward on a kickoff. The ball had to go backward or laterally. By standing alongside Dillon, Johnson was able to reach back to place the ball under his jersey, thus keeping the play legal. Doing it this way also screened what was he was doing from the prying eyes of the Harvard defenders.
Another potential hurdle that has to be cleared is the official. An official who is unfamiliar with the play may incorrectly disallow the touchdown and penalize the team for running it. Warner took care to inform the Referee, Mike Thompson of Georgetown, that the play was to be run so that he would pay special attention to the handoff and make sure that it was legal.
By paying attention to all the little details, including selecting a ball carrier with speed, especially for a big man, Warner pulled off a trick that is still being talked about over a century later.