number of concussions. In 2015 in the Ivy League, a Division 1 conference of 8 private universities in the National Collegiate Athletic Association (NCAA), kickoffs accounted for 6% of all plays but 21% of concussions. In response, Ivy League football coaches recommended a rule change. In 2016, the kickoff line was moved from the 35-yd to the 40-yd line and the touchback line was moved from the 25-yd to the 20-yd line. The intention was to have more kickoffs land in the end zone and thereby reduce the likelihood the receiving player will advance the ball, thus increasing touchbacks. However, moving the touchback line to the 20-yd line could cause receivers to try to advance the ball, possibly decreasing touchbacks.
We investigated whether the experimental rule was associated with changes in the number of touchbacks and the rate of concussion in kickoffs in Ivy League football.