Good buy bets at craps

25 July 2019

By John Grochowski

QUESTION: I was playing craps my usual way. I bet pass and take full odds up to 5x. Then I place 6 and 8 – whichever one isn’t the point, or both if neither is the point.

I noticed this guy a couple of spots away from me who kept buying 4 and 10. When I first learned craps, I learned buying reduced the edge a little from placing those numbers, but that still left bad bets.

He noticed me looking at him, a little quizzical, I guess, because he finally said, “You only pay commission on winners here.”

Does that make buying 4 and 10 worthwhile?

ANSWER: Buy bets work like place bets, except that in exchange for a 5% commission, the house pays your winners at true odds. Instead of the 9-5 you’d get when winning a place bet on 4 or 10, you’d be paid 2-1.

If you pay the commission on every bet, win or lose, buying 4 or 10 reduces the house edge to 4.76% from the 6.67% on place bets.

If you pay the commission only on winning bets, that means you’re paying the commission an average of once per three trials. Your effective commission is one-third of 5% per decision, or 1.67%.

Since the winning bet is paid at true odds and the house is making all its money from the commission, that leaves a house edge of 1.67% on buy bets on 4 or 10.

That’s not much more than the 1.52% on your place bets on 6 or 8.

If you buy 5 or 9, edges are 4.76% if paid on all bets, and 2% if paid only on winners. Don’t buy 6 or 8. The 1.52% edge on place bets is lower than the 4.76% with buy commissions on all bets or 2.27% with commission on winners.

A caution to low-rollers: A $1 commission is 5% of $20. Bets of less than $20 would leave 5% in fractions of a dollar, and casinos aren’t going to want to make change.


QUESTION: My wife and I have a budgeting question. We take $200 for a day at the casino and split it between us. I play 25-cent video poker and she plays penny slots, so her average bets are maybe 40 cents and mine are $1.25. I say to get the same play, I should take $150 and she should take $50. What do you think is fair?

ANSWER: Oh, boy. Deciding what’s fair in someone else’s marriage is not my specialty. Some would say that what’s fair is for each of you to take $100 and do what you want with it. But that’s really something for you to work out for yourselves.

Now if you want to rephrase the question as “What division would lead to the same average losses for each,” that’s something I can work with.

Assume her penny slots return an average of 87% and your video poker games return 97%. I don’t know what pay tables are available to you or how skilled a player you are, but that gives us a starting point.

Per 100 plays, you would bet $125 and she would bet $40. Your average losses would be $3.75, while hers would be $5.20. So if your goal is equal average losses, then she needs the larger share of your $200.

I’d suggest something more flexible. Perhaps starting at $100 apiece and then sharing if one is winning more than the other would work. But it’s really up to the two of you.