It’s pretty clear you don’t understand how sports books make money from sports betting. It certainly isn’t “by chance”, but they also do not care at all what the result of the game is. They make money by setting lines so that equal amounts are bet on each team and paying off winners with the losers’ money, but paying the winners less than what the losers bet. The last thing on earth they would want is rigged games. Rigged games would only reduce action and jeopardize their profits.
There is legal gambling... And then there is gambling. The house always wins, but illegal gaming relies on outcomes that are certain. There are players and refs who are making those outcomes certain. You can lay bets on the entire game, on props and on scores during each quarter of the game... That’s where refs and players on the take come in. The idea that the NFL is completely clean is foolishness.
Remember that one ref that they found shaving points during basketball games... Tim Donaghy... He was the only one who ever shaved points and he did it all by himself with nobody else involved... That was nonsense... He colluded with others and many of those ‘others’ were connected with illegal gaming.
It happens. Anybody who thinks it doesn’t is being obtuse.