I know I give up 1.4% on a pass line bet in craps and 5.26% on a roulette bet. What is the true disadvantage in a standard bet $11 to win $10 wager betting sports?
The bet-$11-to-win-$10 scenario applies to pointspread wagers, where the point adjustment ostensibly makes the result a 50-50 proposition and you can look at it this way. If you’re 50/50 to win a sports wager, you should win one out of two bets. So, after betting $11 to win $10 on two games, you book a $10 win and an $11 loss for a net of -$1. Since you lose $1 after betting $22, the edge is -1/22 = -4.55%. But here’s something interesting. When you look at it from the bookie’s standpoint, his edge is greater. The bookie wins $1, but only risks $10 on each game. That’s 1/20 = 5.0%. From your prospective, though, the -4.55% is the important number. As you’d expect, the disadvantage drops when you find a -105 shop (online books or specials, such as the long-running Thursday-night promotion at the LV Hilton). Now you’re betting $10.50 to win $10, so the calculation is -.5/21 = -2.4%.
Those are the numbers under the assumption that it’s a coin flip. Realistically, sports betting is a lot like blackjack, in that the real edge fluctuates according to what the spread should be compared to where the line currently stands. That’s why sports betting is one of the potentially beatable gambling games. For more information on how the line is set, moves, and can be exploited, see the article "Irrational Exuberance in the Sports Betting Marketplace: How to Win Fading the Steam" by Fezzik at LVASports.com.
