The odds listed are a primary way of gauging the play in the game. There are hundreds of mismatches every single year and the leveling of the playing field has been very helpful in resolving that particular problem. With the use of odds, bookies are able to acquire an equal number of wagers on each team, which assures them that they get money regardless of who wins.
As already mentioned, there have been sports bets since the first sports events. There is evidence that bets were placed on the first Olympic Games in ancient Greece. The bet was placed on the winner of a race or the winner in wrestling. The more matches there were to the games, the more bets there were. The Romans made bets on almost everything that was possible. Among them also the bloody gladiator fights and chariot races. From the very beginning, fraud and manipulation were a means of winning a competition. The Roman Emperor Nero even bribed so much at the Olympic Games in his own country that he won in six different disciplines. One of them was the car race and that although he fell off the car, which normally leads to disqualification. The Olympic Games were then discontinued, but not the sports betting. In the last century there was again a time when sport, especially boxing and horse racing, fell into the hands of criminal gangs. The image of sports betting had to suffer a lot from this bad influence, also because Hollywood used the topic as the basis for many films, as a result of which perception in society drifted further into the negative.
Understand that negative odds indicate how much money your must spend to make $100. When betting on the favorite, you take less risk, and thus earn less. When betting on a favorite, the moneyline is the amount of money you need to spend to make $100 profit. In the previous example, in order to make $100 of profit betting for the Cowboys, you would need to spend $135. Like positive odds, you earn back your bet when winning.
Money Line: More common in baseball and hockey, pro football moneylines are growing in popularity. There is no spread, so your team just needs to win the game, not win by a certain number of points. The negative value means a favorite (-190) and a positive one indicates an underdog (+170). Picture the number 100 sitting in between these two values. Example: if you want to pick a -190 favorite, you must risk $190 in order to win $100. To back a +170 underdog, you put up $100 and win $170 if the dog wins. In some cases, betting moneylines is actually better value and can provide a bigger profit for less risk.