How do odds work in sports..

How do odds work in sports ?

We all come across a word called “odds” but we often ignore it . The reason for ignoring may be that it stretches our brain muscles beyond limit or we consider it as unethical. As a cricket fanatic I used to see this word flashes on TV screen before every important match of a tournament or even odds are calculated for every match of IPL. People often use the word “Odd” and “Probability” interchangeably. But these are two different words with different meanings.
ODDS are just alternative way to express the likelihood of an event. In odds calculation favored events are calculated against unfavored events. Whereas in probability favored events are calculated against total events.
Odds = Probability / 1-Probability
Probability=odds/1+odds

Odds in sports represents the contract between the person who bets and the casino or sportsbook. The person who bets is being called as bookmaker, oddsmaker or a bookie. The odds specify the return which bookie will get in case the side he select wins. If the side loses then he loses the entire bet.

Betting odds
Betting odds are set by the bookmaker for each game in advance. It means how much bookmaker wins on a single currency he bets. For example if the odds are 2.1 for winning the game it means for every currency he bets bettor will get 2.1 in return if he wins.

Traditional Odds (British odds)
Traditional odds are usually expressed as a ratio, such as 4-1, which means that for every dollar bettor bet on the underdog, he will get $4 in return if his side wins.

Spread Bet
In this type of bet, one team beat another by at least a certain amount of points. So if bettor bet on the underdog +7.5 points, it means that if they lose by less than 7.5 points (or if they win), bettor win the bet. Alternatively, if bettor bet on the favorite in this example, they would have to win by more than 7.5 points for bettor to win.

Betting Lines
Betting odds in the US sports betting are called "lines". If there is a "+" sign before the number, the number after it represents how much bettor will win if he bet $100. If there is a "-" sign, the number represents how much bettor have to bet to win $100. For example,
• "+200" means that if he bets $100, his total win would be $300 (equivalent to "2/1" or "3.00").
• "-200" means that he has to bet $200 to win $100 (equivalent to "1/2" or "1.50").

Straight Wager
Betting on the output of a single game.

Parlay
Betting on the output of 2 or more games and bettor has to guess the output of every single game right in order to win the bet.