Last night, the National Football League got to actually use the new rules that they have for Super Bowl overtime (and, I believe, for the playoffs as a larger entity). Apparently the Chiefs knew what the rules were and the Niners were learning about them from the scoreboard at Allegiant Stadium, which seems a little weird to me, but I digress.
Basically, the new rules guarantee each team a possession in overtime, as opposed to the old way where if a team won the coin toss and scored a touchdown on their first possession the game would end.