How to Bet Parlays in Sports

Parlays generally carry a higher house edge than straight bets, which means you give the book a bigger advantage over you when you play them. That, by itself, is reason enough to suppress the misplaced feelings of greed combined with fear that often lead to betting parlays. People think they are risking less with parlays, but they are not. They believe they can win more with parlays, but they cannot. The higher win with parlays is far outweighed by the higher probability of losing. Parlay bettors are actually risking more, with less probability of collecting.

A parlay is not a single bet. It is two bets — a one-unit bet on one team and a two-unit bet on the other. Which team gets the two-unit bet? In point-spread betting at constant money odds, if both teams win or both teams lose it doesn’t matter which team gets the double bet. When one team wins and one team loses, however, the double bet is presumed to have been on the loser. How smart is that for the bettor? Go ahead, make a parlay. We’ll wait until both games are over, and in case of a split we’ll put the double bet on the loser. If your bookmaker sold you a parlay with that line, how many of you would still make the bet?

A parlay is also bad money management. In a parlay you either bet double on the second team, or nothing on that same team, depending upon whether the first game won or lost. That adds an element of luck to your betting that doesn’t need to be there. The skilled handicapper is always seeking to make smart investments. He tries to eliminate the effect of luck to the greatest extent possible in order to make his results as predictable as possible.

As with every rule, however, there are exceptions. The exception to the rule regarding parlays occurs when the two bets are co-dependent.

I knew one bookmaker who was taken for tens of thousands because he didn’t understand the co-dependency of certain bets. He allowed a player to consistently parlay the first half with the game. The player parlayed totals by combining the over in the first half with the over in the game, and the under in the first half with under in the game. Both parlays were made in the same game. Each time the player won he would win 2.6 times his bet. Betting $100 on each parlay, if one of them won, the player would win $260 and lose $100 on the other parlay for a net win of $160. He could never win both parlays. If he lost both parlays he would lose $200.

At first glance, this appeared to be a great opportunity for the book. The normal coin-flip odds of winning one parlay o