Substitution Rules and Football's Evolution

Football's substitution rules have changed as often and altered the game as profoundly as almost any rules category. Only the transition from rugby's scrummage to the scrimmage, the addition of the system of downs, and legalizing the forward pass have had a more significant impact. Still, while the game's substitution rules changed numerous times before the 1940s, they did not reshape football until two-platoon football became legal. In the case of college football, this did not occur until two-platoon football became legal for the second time.

Like rugby, early football did not allow substitutes by convention, not rule. Football's first set of rules in 1876 did not mention substitutions, stating only that "the number of players shall be limited to fifteen upon a side." That changed in 1882 when substitutes were allowed to replace disqualified or injured players and again in 1897 when substitutions could enter the game at the captain's discretion. The 1905 rules allowed substitutions at any time, assuming the incoming player reported to the referee before lining up, and also formalized the convention that substituted players could not return to the game.

Limited or no substitution was the norm in the sporting world back then. For example, substituted baseball players could not return to the game. Ice hockey prohibited substitutes other than replacing injured or disqualified players. High-level soccer first allowed subbing in 1965, and rugby still does not have subs (other than blood replacements).

Even when football began allowing limited substitutions, the manner differed from today. Most substitutions occurred late in games when the starters tired. Substitutions also occurred when strong teams started their reserves in early season games against lesser opponents to save their top players for the season-ending big games. Squads that met unexpectedly strong resistance in those games sometimes sent out first-string players to mop up and ensure the victory. In rare circumstances, coaches sent in reserve players who were effective kickers, but even those substitutes had to play a regular position after that.

Harvard's V. P. Kennard, a fullback and effective kicker, was substituted into the 1908 Yale game late in the first half. On his first play in the game, the lefty drop-kicked a field goal for the game's only score, giving Yale its 4-0 victory. (Davis, Parke H. Football: The American Game, 1911)

A side effect of players being unable to return to the game was that dazed or otherwise injured players often stayed on the field, taking time to recover before returning to play.