NFL teams returned 75.6 percent of the kickoffs in Week 1, the highest rate in the league in 15 years, after moving the touchback to the 35-yard line.
The rate last season with touchbacks spotted at the 30-yard line was just 32.8 percent.
The rate of 75.6 percent (118 of 156) was the highest since Week 17 of the 2010 season and the highest in a season-opening weekend since 2010 (78.1 percent), according to ESPN.
The league has altered the kickoff rules over the years to try to minimize the number of injuries resulting from high-speed collisions. Kickoffs now begin with most players standing downfield, unable to move until the ball touches the ground or a member of the return team.