The NFL is considering a new rule allowing teams to elect to try and convert a fourth-and-15 play from their own 25-yard-line instead of kicking off. It's an interesting idea that, in theory, could keep trailing teams in the game for a longer period of time, allowing them to score and then try and retain possession with a higher probability of success than an onside kick. The only issue is, it could also be used against those trailing teams.
This rule was previously discussed and included a clause that only trailing teams could utilize this opportunity. However, the new rule doesn't have that language in it.
Because the play is timed, the issue with that is if a team is leading and there's only a few seconds left on the clock, they could elect to keep the ball and run around and kill the clock, thus avoiding the possibility of a kickoff return for a touchdown. It doesn't happen often, but the possibility does exist.
A team can only use this rule twice per game and there's obviously a big risk starting at your own 25. But with only five seconds left on the clock, a quarterback could run around for three seconds and then throw the ball as high and far out of bounds as they can and kill the clock. There's the possibility of things going awry on that play too, but teams will practice it enough to limit their exposure. Think of it as the new victory formation.
The rule still needs to be voted on and there's a lot of good reasons for it to be passed. But this one element would change the end of some games, which would be fun and weird at the same time.