Here's a story about a pair of brothers who were on the football field when teams executed two of football's best-known plays for the first time. They were on offense the first time and defense the second. Notably, neither play resulted from a rule change. Instead, the new plays resulted from the inventiveness of the team's coaches or team members.
The Bliss brothers, Laurie and Pop (C. D.), played together for Yale in 1891 and 1892, when the Bulldogs won 26 games in a row, two IFA championships, and were retroactively named college national champions. Yale didn't have much competition then, but with Walter Camp as their coach, they were the best of the time and were in the middle of the game's development.