The payoff for football, basketball, and hockey is $100 for every $110 wagered, unless otherwise noted. Therefore, $110 will be wagered if you specify a $100 straight bet.

At odds of 100/110, only 52.5% of your bets have to win for you to overcome the bookmaker's profit and break even. As a result, the bettor only need a very small edge to become a winner. Some sports bettors win 55- or even 60% or their bets.

Parlay bets are another story. The actual odds of picking two winners is 3 to 1, but a typical payout is 2.6 to 1. This gives the sportsbook a 10% advantage, and that's too much! Worse still, the odds usually get even longer when you add more games to your parlay. In a nutshell, it's best to avoid parlay bets.