SPORTS BETTING GUIDE

Straight Bets
Straight bets are bets placed on a side or a total in Football or Basketball and only totals in Baseball. A straight bet on a side usually involves a point-spread. In this case you are wagering on a team to win the given time period on which you wager (game, 1st, 2nd half) after the score is adjusted by the particular point-spread. When you wager on a total you are wagering that the score of the game for the given time period (game, 1st, 2nd half) will be over or under a designated number. In either of these two bets you are laying 11 to win 10 or some variance of those odds, an example being bettors playing one side will lay 12 to win 10 and bettors playing the other side will lay 10 to win 10.

When wagering on game totals you are betting on the combined score of the game to go over or under the designated number for the time period of your bet, i.e. 1st half, half time or full game. Total wagers on the full game or 2nd half include overtime periods except in the case of Soccer when three way betting is offered ( the tie is offered as a betting option). If the tie is offered as an option overtime is not included in the calculation of the game total.

Money Lines
Money Lines are used to some degree in most major sports. In a money-line bet you are wagering on the outright winner of the contest independent of any point-spread. For every money line there is one number for each of the two sides of the play, the underdog and the favorite. An example of a money-line in football is:

Redskins -140
Eagles +120

In this example the favorite is denoted by the minus sign and the underdog by the plus sign. You would wager $140 to win $100 on the Redskins (the favorite) and you would wager $100 to win $120 on the Eagles (the underdog). Because no point-spread is used to determine the winner you must risk more money to win less on the favorite and vice-versa on the underdog.

Parlay
A parlay is a wager in which you pick from 2-8 teams or totals to win in order to receive a larger payout for risking less money. For a parlay to be considered a winner all selections must win. In the event of a tie the parlay will revert to the next lowest number of winning teams and payoff accordingly (a 2 team parlay reverts to a straight bet). You can mix different sports into your parlays and even create parlays from one game. You cannot parlay money lines to the same side of the game or 1st half to 2nd half or the same side of the game.

Money Lines
Money lines are another popular way to bet on sports. In a money-line bet you are wagering on the outright winner of the contest independent of any point-spread. Naturally one team will be favored most of the time so if you want to bet on the favorite you must bet more than you stand to win (laying odds). If you bet on the underdog you stand to win more than your bet (taking odds). For every money line there is one number for each of the two sides of the play, the underdog and the favorite. An example of a money-line in football is:

New Orleans -210
Baltimore +170

This means that if you prefer to bet on the favorite, New Orleans, you must wager $210 for every $100 you win if New Orleans wins. If you prefer to bet on the underdog, Baltimore, you win $170 for every $100 you wager if Baltimore wins.

The way a money line is established is first the bookmaker uses his best judgment to determine the probability that the favorite will win. For example let's assume 60%. He then converts this to a fair money line with no house edge. If the probability is p then the money lines are +/- 100*p/(1-p). If p is 60% then the fair money lines would be +150 and -150. Then the bookmaker will take a constant and add it to the amount the favorite better must bet and subtract is from the amount the underdog better can win. A common constant is 10 points. In this example the bookmaker would adjust the money lines to +140 and -160. This is referred to as a 20 cent line, referring the total line movement from the theoretical fair line. For games with a strong favorite the numbers of points will increase.

If the two money lines are x and y (for example x=+140 and y=-160) then the house edge on the taking odds (or betting on the underdog) is (x+y)/(200+x-y). The house edge on the laying odds (or betting on the favorite) is -100*(x/y+1)/(200+x-y). In the +140/-160 example the house edge on the taking odds is 4.00% and laying odds is 2.50%. If the player must lay odds on either team (for example x=-105 and y=-115) then the house edge on x is ((20000/x)+x-y+200)/(x-y+400) and on y is ((100/y)*(x-y+200)+200)/(x-y+400). In this example the house edge on x is 4.76% and on y is 4.24%

Teaser
A teaser is similar to the parlay bet in that you choose multiple events and have to win them all. However the bookmaker teases the player with a specified number of extra points for each team bet on. Naturally the player pays for these extra points in the form of lower payoffs than on a parlay bet.

Reverse
A Reverse is a wager on all the possible combinations of a two team double action if-bet with the option to pick 2-3 teams. An example of a 2 team Reverse is:

Eagles -7 110/100 Padres +135 100/135

Here you have two if plays on the Reverse: Eagles/Padres and Padres/Eagles. If the Eagles win, your bet for the Padres stands and vice-versa. Your maximum risk in this situation is $220 provided you risk $110 on the Eagles to win $100 and $100 to win $135 on the Padres. If you risked the $220 you stand to win $470. Reverses must be played by phone and are always double action, you cannot have open spots and are from 2-3 teams.
You can buy up to 1 point.

Buying Half a Point
The straight bet player has the option to move the point spread 1/2 point to his advantage. The cost of this half point is laying 120, as opposed to 110. The most opportune time to buy a half point is when one team is favored by 2.5, 3, 6.5, or 7. This is because many games end in a 3 or 7 point difference and the extra half point can either turn a loss into a draw or a draw into a win. However many sports books do not allow purchasing a 1/2 point on these spreads for exactly this reason. Over 1975 games during the 1993 to 2000 seasons the overall house edge by purchasing the extra half point is 4.13%.

Futures
Proposition bets usually pay long odds that a specified team will win the playoffs or the season championship. For example before the beginning of the 2000 baseball season a bet that the Baltimore Orioles winning the world series paid 35 to 1 odds.
To calculate the house edge on a set of futures bets follow these steps:

Convert all winning odds to a fair probability of winnings. For example if the Orioles paid 35 to 1 odds then a fair probability of winning would be 1/36. In general if the odds pay x to y then the probability of winning is y/(x+y).
Add all the probabilities form step 1. Call this total t.
The overall house edge on all futures bets is 1-(1/t).