Lay bets in craps

As I understand it, when betting on the "lay 10" or other number in craps, the bet returns true odds (here 1:2), but the casino charges 5% commision on the bet. The free craps player on this site states that "that corresponds to 19:41 on the 4 and 10". Does anyone know how to arrive at this figure? 41 seems like a strange number if the commission is 5%. What am I missing?

Hi rdt, and welcome to the forums.

Quote: rdt

As I understand it, when betting on the "lay 10" or other number in craps, the bet returns true odds (here 1:2), but the casino charges 5% commision on the bet. The free craps player on this site states that "that corresponds to 19:41 on the 4 and 10". Does anyone know how to arrive at this figure? 41 seems like a strange number if the commission is 5%. What am I missing?

I think that's just the fractional representation of the percentage that best represents the true odds after commission.

i.e. Say you make a $100 wager on the lay 10... True odds are 1:2, which means you'd win $50 on your $100 wager... However with the 5% commission you'll only win $45 on your $100... So 45/100 = .45, while 19/41 = .46. Not sure what went in to the 19/41 response exactly, but again I would think it's just the best fraction for displaying the actual percentage odds after the commission is factored in.

Well, sure the difference is minuscule, but still I think it makes sense to understand the arithmetics of the game. If our reasoning was right, it should be stated as 9 to 20. Or if the commision is only based on the winnings, it should be 19 to 40. But why 19 to 41? I still don't get it.

There are a few ways to come to the figure.

First of all, lay bet commission is based on the amount you WIN, not the amount you WAGER. So a $200 lay paying $100 would have a 5% commission on the $100, or $5.

Some casinos require vig up-front.

Meaning you'd bet $200 and have to pay $5 just to make the bet, and no vig taken once you win (since it was taken up-front).

Therefore, you're betting $205 to win $100, but you don't get that $5 back. So you're betting $205 to win $95.

95 / 19 = 5
205 / 41 = 5
5 / 5 = 1

therefore:
95:205 == 19:41

Quote: rdt

Well, sure the difference is minuscule, but still I think it makes sense to understand the arithmetics of the game. If our reasoning was right, it should be stated as 9 to 20. Or if the commision is only based on the winnings, it should be 19 to 40. But why 19 to 41? I still don't get it.

Your first bet requires $40 + $1 vig to make the bet. You win 20 - $1 vig. Places that do it right will refund you the vig if you want to take off a buy bet. So if you wanted to make the bet and take it off after a win, it pays 20 to 41. We're getting into mathematical semantics here. 19 to 41 means that you are playing at a place that charges commission to place the lay bet AND you decide to always keep the bet up.

Quote: ahiromu

Your first bet requires $40 + $1 vig to make the bet. You win 20 - $1 vig. Places that do it right will refund you the vig if you want to take off a buy bet. So if you wanted to make the bet and take it off after a win, it pays 20 to 41. We're getting into mathematical semantics here. 19 to 41 means that you are playing at a place that charges commission to place the lay bet AND you decide to always keep the bet up.

It's 19 because you lose the $1 vig always - win or lose. Whether you keep the bet up or not doesn't matter.

If you have $41 to place the bet and win, you will now have $60 total (40 lay + 20 win) - a net gain of $19.

Quote: wudged

It's 19 because you lose the $1 vig always - win or lose. Whether you keep the bet up or not doesn't matter.

If you have $41 to place the bet and win, you will now have $60 total (40 lay + 20 win) - a net gain of $19.

One place I've played at, I think it was Tunica Horseshoe (could be wrong there), refunded the vig if you removed the bet. That said, the offer was before it had hit, but I doubt it'd be different.

Quote: ahiromu

One place I've played at, I think it was Tunica Horseshoe (could be wrong there), refunded the vig if you removed the bet. That said, the offer was before it had hit, but I doubt it'd be different.

Yeah, casinos give you the vig back if you take the bet down. I haven't seen one that doesn't.

Quote: RS

...you'd bet $200 and have to pay $5 just to make the bet, and no vig taken once you win (since it was taken up-front).

Therefore, you're betting $205 to win $100, but you don't get that $5 back. So you're betting $205 to win $95.

95 / 19 = 5
205 / 41 = 5
5 / 5 = 1

therefore:
95:205 == 19:41

I think this pretty much explains it. I expected that it was the mechanics of the commision that I was wrong about. It would be strange if the casinos didn't charge the vig up front, because then you'd owe them 5$ if you lose.
Whether you keep the bet up after a win or not shouldn't matter, because if you want to make a new bet, you'd also have to pay a new vig. If you take the bet down before the bet is resolved, of course the casino should pay the vig back.