Team A must beat Team B by atleast 7 points. The payoff is double. The bettor must bet 11-10. If you take bets of more you will make more than that in a year. Because if you can not pay off the bets that people won you will get your ass kicked if not killed and will not be able to have a gambling ring because no one will place bets with you if you can't pay off.
Numbers is another profitable type of gambling.
People choose a number from 000 through 999 and write the number on a piece of paper with their name. The runners collect the number paper and money from all the people and drops it off to you. The state lottery pick-3 number drawings each day are used for choosing the winners. You need to pay off better than what the state lotteries do because it would be more profitable to do business with you if you can offer a higher pay off on winning numbers, also people don't have to pay tax on winnings if they go through you. The odds of a person winning is 1000 to 1.