Juice, a.k.a vig, is the commission added to a bet by the sportsbook to guarantee their profitability. The standard value is 10% (charged to the loser - the winner always gets his bet and juice refunded), but there are many online sportsbooks offering reduced juice of 7% or even 5%.

Juice on Spread Bets

When looking at spread betting - bets on the point spread wagering line - the effects of juice are easy to calculate. Take the following example:

• Team XYZ -4.5 (-110)

• Team 123 +4.5 (-110)

Timmy bets $110 on XYZ in order to win $100. Billy bets $110 on 123 to win $100. The book collects $220 total and awaits the event's outcome. When the game is settled, the book pays out $210 to the winner - a refund of his $110 bet, plus $100 in winnings. The book keeps $10 for itself.

The book's advantage, or theoretical hold, is calculated as $10/$220 = 4.55%. The sportsbook has a 4.55% advantage over the bettors if the juice is -110.

Juice on Moneyline Bets

Online Sports Betting System is a moneyline betting system. Calculating the juice built into a moneyline is a bit trickier. There are several ways to do it, but we have found that converting the odds to probabilities (or percentages) and then adding them up is the easiest to follow. For example:

• Team XYZ +200

• Team 123 -220

Team XYZ is $100 to win $200 or 2/1 odds. Multiply 1 X 100 and divide by 3 and you get 33.33%

Team 123 is $220 to win $100 or 5/11 odds. Multiply 11 X 100 and divide by 16 and you get 68.75%

Add the two together to get 102.08% - this is known as the overround, the sum of all the bet probabilities. The juice is just 1 - 100/overround = 1 - 100/102.08 = 2.041%

Juice Free Bets

The OSBS method wrings the juice out of sports betting by comparing the value bet posted by a sportsbook to its opposite on an exchange. Thus we would find the lines to be:

• Team XYZ +200 (our value bet at a sportsbook)

• Team 123 -200 (at a betting exchange)

The overround works out to exactly 100% on this combined line, and the bet is theoretically juice free. This turns out to be another aspect that adds value to the bet selections of the Online Sports Betting System.