At one time, it was impossible for those wishing to wager on football to do so with out heading to the casinos. Thanks to the advent of online gaming, access of a legal and legalimate football sportsbook (a gaming "house" for sport wagering) is now possible.
However, there is more to it then just picking the winner of the game and collecting your winnings. There is a bit more to the process. Football bets do not payout based on straight bet, a bet with no modifications to the final score. Instead, spreads and odds play a role in the wagering process. This is where a sportsbook comes into play. A solid, reliable sportsbook will set equitable betting lines that provide a fair playing field for the player and the house.
Why are straight bets not employed? Basically, some teams are better than other and if a team with a 12 - 0 record were to play a team with a 1 - 11 record, 99% of the wagers would be on the favorite. This would break the bank of the house if the favorite were to win. This is an unsustainable business model which necessitates the concept of odds and lines.
Basically, a sportsbook will offer a line where a handicap is placed on the favorite. A certain amount of points will be taken away from the favorite and given to the underdog. This is why you will see a numerical figure and a minus sign next to the favorite team. This figure is factored into the final result of the game.
For example, if the Eagles are (-2) against the Cowboys, the Eagle must win by three for anyone betting on them to collect. Similarly, if someone were to get on the Cowboys, it would be possible to win the wager if the Cowboys lose by 1. If the tallied end result is a tie, then the game would be a push.
Another bet is offered within football betting that entitles an over and under bet. As the name implies, you would wager on whether the combined final score is higher or lower than a predicted number. So, if the over and under is 30, you can wager on whether or not the tally will be above / below 30. If you betted on the over, and the final score was 21 - 14, you would win since the combined tally was 35.
This means it is possible to place bets on both the game itself and on the over / under. Some may opt to use the over / under as a hedge despite many look to "clean up" and win both bets. In some instances, this is the actual exit.
No, the figures of the odds are not randomly pocked out of thin air. They are based on careful research in the teams' lineups, win-loss record, injury reports, and other factor.
Of course, different sportsbooks will have different lines. However, the numerical range will not be too significantly different. Again, the lines are based on legitimate factors and not on unempirical data. As long as you are signing on with a legitimate sportbook, you should not have these problems.
Finding a reputable sportsbook can be at times like looking for a needle in a haystack. Yet with a little research on the interenet you will be in the game before you know it.