Even though betting on basketball, football, and baseball is illegal in all but two states, the United States federal government estimates that sports gambling is at least an $80 billion per year industry, with some estimates going as high as $350 billion annually.

Betting on sports takes work. Unfortunately, many people who place bets on online sports betting sites lose their money. There are a several common reasons for this:
Betting on a favorite team: People place bets on their favorite teams regardless of the facts. They bet with their hearts and not their heads. People find it impossible to bet against their favorite team even though the record clearly shows they are backing a loser.

Failure to be Selective: Some people who place regular sports bets have to have action on many games at the same time or they simple bet on any game if it is on TV. It's not uncommon to see a player betting on 5 or 6 NFL (football bets) or NBA (basketball bets) games on a given day. Players who just have to have a bet on Monday night football lose more money because they place a bet just because the game is on TV. It can be a bad game but they will bet it. 

Failing to do the Research: The majority of sports bettors are lazy. They don't want to spend the time studying the game they love so much. They would rather take the advice of a sports columnist or pay a service to try to pick a winner for them. This does not always ensure that the wisest bet is placed.

Straight Bet: A straight bet is a wager on one team to win or a total to go over or under, whose outcome for wagering purposes is determined by a point spread and/or money line odds.

Parlay Wager: A parlay wager consists of picking teams or totals and putting them together into a single play or wager which is going to have only one risk. In a parlay you can combine any sport as long as it is not a circled game.

In parlays, the payoff is determined by the number of teams picked and can be changed if any team in the parlay has a money line; there is no buying points. The number of teams that you put in your parlay decides how much you can win.

If you would like to risk less to win more, then Parlays are the bet for you. A parlay is just a collection of straight bets. The trick is that all of the straight bets must win for you to win your bet, however the pay out is much better.