lets say i bet 50% of the bets on the winning guy. (in this case, lets say 10k total bets on winning guy and 10k on losing guy, i bet 5k on winning) Then in return, I get 50% of the bets on the losing guy since i bet 50% winning. This is calculated after the house and the profit the winning guy gets for winning is taken out. (so you get roughly 4k back).
If I am wrong, please ignore me. I could just be dumb.