For example: If it is universally believed that Alaska State is better than Hawaii Tech, a standard win/loss wager wouldn't work, since most likely people would bet more money on Alaska State. Therefore, the Sports Book could put the point spread on Alaska State at 6.5 points. This would mean if you bet on Alaska State, not only would they have to win the game, they'd have to win by at least 7 points to make you a winner, otherwise a ticket on Hawaii Tech, even though the team might have loss, would be a winner.
As you can see above, the combined score for Superbowl XLV was 56, and since this line was offered at reduced juice, a wager on the over at 44.5 of only $105 would yield a profit of $100. This line closed at a high of 46 points at some books, demonstrating how the public, who tend to show a proclivity for high scoring games, can increase an O/U line.
Totalizators. In totalizators (sometimes called flexible-rate bets) the odds are changing in real-time according to the share of total exchange each of the possible outcomes have received taking into account the return rate of the bookmaker offering the bet. For example: If the bookmakers return percentage is 90%, 90% of the amount placed on the winning result will be given back to bettors and 10% goes to the bookmaker. Naturally the more money bet on a certain result, the smaller the odds on that outcome become. This is similar to parimutuel wagering in horse racing and dog racing.
In general, the betting public tends to gravitate towards favorites when betting the games regardless of the actual pointspread. This is especially true with high-profile teams such as Dallas and Green Bay in the NFL and Golden State and Cleveland in the NBA. The sportsbooks are well aware of this phenomenon and often times they will adjust the betting spreads accordingly. This, in turn, actually adds some value to the underdog when you consider that a pointspread is nothing more than a handicapping tool that is designed to even out the match.
Teasers are similar to parlays except the point spread on each game moves a certain number of points in the player's favor. In football the player gets 6 to 7 points, and in basketball, 4 to 5 points. The player pays for this in the form of much lower winnings. For example, if the Vikings were part of a 6-point teaser, then they would only need to win by more than 4 points to cover. If the Rams were part of a teaser, they could win, or lose by less than 16, and cover.
The divisional round of the NFL playoffs concludes on Sunday, and we’ll know which four teams have a chance to win Super Bowl LIII after two must-watch games. Tom Brady and the Patriots will try to earn their fourth consecutive AFC Championship berth, but is it finally Philip Rivers’ year? In the NFC, Nick Foles led the Eagles to a stunning upset of the Bears, but can the defending Super Bowl champions take down the No. 1 Saints?
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%.