The amount that you get back for a winning sports bet will depend on two factors: the amount of your wager and the odds at the time you placed the wager. While the numbers may shift after you place it, you'll be locked in at those odds as soon as the sportsbook accepts the bet.
Bookies make money by charging a fee on each bet they take, known as the "vigorish" or the "vig, and pay out money when their customers win a bet. Their goal, understandably, is to make sure that incomings exceed outgoings.
