One of the most popular prop bets every Super Bowl Sunday is the length of the National Anthem. Before the Chiefs and 49ers kicked off Super Bowl LIV, Demi Lovato's rendition came in at 1:49, well under the mark set by Las Vegas oddsmakers. Leading up to the game, the mark was largely set at 1:55.The average length of the National Anthem performance at the Super Bowl is 1:57, but Lovato's version exactly matched the mark set last year by Gladys Knight. Before that, you'd have to go back to Super Bowl XLVI in 2011 to find a version of the Anthem that came in under 1:50.While this was Lovato's first time performing at the Super Bowl, it was actually her sixth time performing the Anthem at sporting events, and including the Super Bowl, five of those performances came in under 2:00.Data from the National Gaming Association predicted that 26 million Americans would place $6.8 billion in bets on the Super Bowl this year, an increase from last year's game of 15%. Of course, sports betting has become increasingly legalized, as citizens across 13 states are now able to gamble on games legally. As more and more states decide to legalize wagering, more and more bettors will race to put money down on the Super Bowl and other major sporting events, placing popular prop bets such as the National Anthem under a bigger and bigger spotlight. We'll see if the under trend continues in 2021.