Boredom Almost Killed the N.F.L. Kickoff. New Rules May Save It.

Tonight, the N.F.L. season will begin with a new and unusual-looking version of the play that’s as old as the league itself: the kickoff.

The impetus for the change was boredom.

Long considered one of the most exciting plays in football, the kickoff has been adjusted several times in recent years, primarily in the name of player safety. But those changes have meant less action. Last year, fans were treated to an actual kickoff return about one in every four plays.

The rule changes piled up:

• In 2011, the kickoff was moved forward 5 yards, to the 35-yard line, making it easier to kick the ball deep into the end zone. That often resulted in a touchback, and the receiving team, instead of returning the kickoff, got the ball at its own 20-yard line.

• Beginning in 2016, a touchback meant starting at the 25-yard line, not the 20, further incentivizing receiving teams to choose a touchback instead of a return.

• And last year, the N.F.L. allowed a kick returner to call for a fair catch anywhere he caught it — not just in the end zone — resulting in a touchback.

Although the league declared the series of rule changes successful in reducing concussions during kickoff returns, its own statement credited the decrease in injuries to the fact that fewer kickoffs were returned.

The N.F.L. is hoping its new rules can keep injuries low while saving the kickoff from irrelevance. What fans will see Thursday night, when the Baltimore Ravens visit the Kansas City Chiefs, is what the N.F.L. is calling a “dynamic kickoff,” an adjustment intended to encourage more returns while limiting concussions caused from hits after long running starts.

If the preseason is any indication, the change appears to have had an effect: Return rates on this year’s preseason kickoffs have more than tripled last year’s regular-season rate.