To show how this can be exploited, take a point spread of -8.5 at odds of -110. This is a 50/50 proposition. Let's assume you've purchased enough points to move the spread to -6.5 at odds of -150. Now, you'd win instead of lose 6.24% of the time they win by 8, and 6.59% of the time they win by 7. Add these together with the 50% from the original proposition, and we get 62.83%.
A point spread - Lets take, for a hypothetical situation on one of the types of football bets (using the point spread), that the Kansas City Chiefs were visiting the Detroit Lions and Detroit was established as a six-point favorite at game time, which is commonly written as Detroit -6. Kansas City would be the underdog and displayed as Kansas City +6. If you bet the favorite, Detroit has to win by more than six points to win your bet. Remember, the Lions are favored by six points, so we subtract six points from their final score on a spread bet. If Detroit were to win 27-20, Lions bettors would win their wager. If the Chiefs were to win the game by any score and you picked the Chiefs you would win not including the extra six points. If the Lions were to win, 20-14, it would be exactly six and a push, so you would get your money back.
In the UK and some other European countries the profit from spread betting is free from tax. The UK and some other European countries tax authorities designate financial spread betting as gambling and not investing, meaning it is free from capital gains tax and stamp tax, despite the fact that its regulated as a financial product by the Financial Conduct Authority in the UK. Most traders are also not liable for income tax unless they rely solely on their profits from financial spread betting to support themselves. The popularity of financial spread betting in the UK and some other European countries, compared to trading other speculative financial instruments such as CFDs and futures is partly due to this tax advantage. However, this also means any losses cannot be offset against future earnings for tax calculations.
When the point spread was invented in Chicago by Charles McNeil the money line took a backseat. When two unevenly matched teams played, the playing field was leveled by having the favorite give points (for example Chicago Bears –7) while the underdog got points (Minnesota Vikings +7). No matter which team the bettor took the bettor would always risk $110 to win $100. The extra $10 needed to win $100 is called the juice or the vig, it is basically the house’s or the bookie’s take. It’s 10-percent of the bet so it would take $33 to return $30 and $440 to return $400 etc. (winning bettors get the vig back).
Anybody who wagers on the 49ers would need them to win by 7 points or more for a winning bet. Those betting on the Rams (+6.5) would need them to lose by 6 points or less (or win) for a winning wager. It's also worth mentioning that a half point is used in many point spreads (such as the -6.5/+6.5) to prevent pushes because no team can score half a point.
Sportsbooks also offer wagering on the total or Over/Under – the cumulative number of points scored by both teams in a game. You can bet on if the final score will go either Over or Under that set total. For example, in a game pitting Team A vs. Team B, the total is 48. A wager on Over wins if the total points scored exceeds 48, and a wager on Under wins if the total points scored falls below 48. If the total lands on 48, it’s a push and wagers are refunded.
With some betting sites odds, certain games are priced differently than risking $1.10 to win $1.00 (which is called -110 odds). For example, you might see the Giants priced at -105 and +7 in a game against the Jets. Now, you only have to risk $1.05 to win $1.00. This is obviously better odds, but it's very likely that they will lose by exactly seven to give you a push. Taking -110 and +7.5 with an alternative bookmaker is actually the better bet.
If you follow football at least reasonably closely, have some idea about the relative strengths of all the players and teams, and have absorbed the information provided on this page, then you should be able to become a competent football bettor. You don't really need to know much else should the aim be to simply have some fun and win some money every now and then.
Sports betting would be easy — or maybe just easier — if all that was required was to correctly pick the winning team. Gambling institutions, sportsbooks and bookies fall back on point spreads to make the process a little more difficult and to create the ultimate wagering challenge. You'll need a solid understanding of the point spread system if you hope to have a profitable season.