How Does the Casino Get Its Edge?

By John Grochowski on Monday July 24, 2017

craps, dice, gambling, gaming, gaming-tips, house-edge

I’m often asked, “How does the casino gets its edge,” and the basic answer always is, “By paying winners less than the true odds of winning.”

Casinos take your full bet when you lose, but pay only a portion of the true odd when you win.

Of late, several people have asked about edges on various craps bets, so let’s look at a couple.

We’ll start with the one-roll bet on 12. There are 36 possible combinations of two six-sided dice. Only one totals 12 – a 6 on each die.

That makes the true odds against rolling 12 35-1, but the usual payoff is 30-1. If you bet $1 on each of 36 rolls and 12 came up once, you would keep that $1 bet and get $30 in winnings for a total of $31. The house would keep the other $5, leaving a house edge of $5/$36, or 13.89 percent.

Some wagers are more complex because they involve multiple rolls. A place bet on 6, for example, could go several rolls before it’s decided. You win if the shooter rolls a 6 and lose if he rolls a 7. No other rolls matter.

Of those 36 possible rolls in craps, six total 7 and five total 6. That makes the true odds of winning the bet 6-5. The house pays 7-6, provided you bet in multiples of $6. If you bet $6 at a time on a streak of 11 decisions that include six 7s and five 6s, you risk $66. On each of the five winners, you keep the $6 wager and get $7 in winnings for a total of $13 per win and $65 for all five.

Since you risk $66 and have $65 at the end of the trial, that mere $1 difference is the house edge, and that comes to 1.52 percent.

The math is more involved with pass, don’t pass, come and don’t come, but the basics remain in place: The house takes an edge by paying less than true odds.