However, the casino says to me, “You are a fine customer and, because of that, we’ll treat your passline bet as a winner if the shooter rolls 2 (or a 12) before rolling a 7 and we’ll pay off your bet. Otherwise, you lose.”
The 2nd paragraph describes a Crapless Table. So, why are the odds on a Crapless Table worse than the odds on a regular Craps Table?
Keep in mind that the come out roll of a 3 offsets a come out roll of 11. What is the ‘math’?
Thanks.
For a 2, 3, or 12, the result changes from a guaranteed loss to a high probability loss (6/7 for 2 and 12; 3/4 for 3), so the expected value does not go up that much.
For an 11, the result changes from a guaranteed win to a 3/4 probability loss, so the expected value goes down quite a bit.
3 does not "offset" 11 in crapless craps the way it does in regular craps.
Quote: CrapsmanThanks. Are you able to support your answer with percentages? I don’t see how the change in House Edge goes from 1.1% to over 5%. Like in grade school, please prove your answer.
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The main issue with your logic is that the 3 doesn't offset the 11. The 3 turns a sure loss into a bet that wins 25% of the time. The 11 turns a sure win into a bet that wins 25% of the time.
Think about what happens on 36 come out rolls. You can expect 1 each of 2 and 12, and 2 each of 3 and 11.
Out of these 6 rolls, in regular craps you have 2 wins and 4 losses (the two 11's win, everything else loses).
In crapless your 2 and 12 win 1/7 of the time each (expected wins = 2/7). Your 3 and 11 win 1/4 of the time each (1 expected win over the 4 rolls). So your have 9/7 expected wins instead of 2. So every 36 rolls, it costs you 5/7 (0.714) wins.
In regular craps, you win approximately 17.75 times and lose 18.25 times every 36 pass line bets. So you of you make 36 pass line bets you can expect to lose about half a bet, for a house edge of about 0.5/36 = 1.4%
In crapless, you only win and 17.04 out of 36 (instead of 17.75) pass line bets and lose 18.96 (instead of 18.25). So you can expect to lose about 1.92 bets, for a house edge of 1.92/36=5.3%
Quote: CrapsmanThanks. Are you able to support your answer with percentages? I don’t see how the change in House Edge goes from 1.1% to over 5%. Like in grade school, please prove your answer.
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Sure, but as some people don't like reading long posts filled with math, I will put it in a spoiler box
The probability of rolling a 2 or 12 on the comeout is 1/18 (that is, 1/36 for each of them). There is a 1/7 chance of winning and a 6/7 chance of losing with a point of 2 or 12, so the portion of the expected value (EV) from a 2 or 12 = 1/18 x ((1/7 x 1) + (6/7 x (-1))) = 1/18 x (-5/7)
The probability of rolling a 3 or 11 on the comeout is 1/9; there is a 1/4 chance of winning and a 3/4 chance of losing with a point of 3 or 11, so the portion of the EV from a 3 or 11 = 1/9 x ((1/4 x 1) + (3/4 x (-1))) = 1/9 x (-1/2)
The probability of rolling a 4 or 10 on the comeout is 1/6; there is a 1/3 chance of winning and a 2/3 chance of losing with a point of 4 or 10, so the portion of the EV from a 4 or 10 = 1/6 x ((1/3 x 1) + (2/3 x (-1))) = 1/6 x (-1/3)
The probability of rolling a 5 or 9 on the comeout is 2/9; there is a 2/5 chance of winning and a 3/5 chance of losing with a point of 5 or 9, so the portion of the EV from a 5 or 9 = 2/9 x ((2/5 x 1) + (3/5 x (-1))) = 2/9 x (-1/5)
The probability of rolling a 6 or 8 on the comeout is 5/18; there is a 5/11 chance of winning and a 6/11 chance of losing with a point of 6 or 8, so the portion of the EV from a 6 or 8 = 5/18 x ((5/11 x 1) + (6/11 x (-1))) = 5/18 x (-1/11)
The probability of rolling a 7 on the comeout is 1/6; you always win, so the portion of the EV from a 7 = 1/6 x 1
The total EV is 1/18 x (-5/7) + 1/9 x (-1/2) + 1/6 x (-1/3) + 2/9 x (-1/5) + 5/18 x (-1/11) + 1/6 x 1 = -373 / 6930, or about -5.3824%
Here is the same thing, in handy table form:
Point | P(point) | P(regular win) | P(regular loss) | P(crapless win) | P(crapless loss) | Regular EV | Crapless EV |
---|---|---|---|---|---|---|---|
2 | 0.0277777778 | 0 | 0.0277777778 | 0.0039682540 | 0.0238095238 | -0.0277777778 | -0.0198412698 |
3 | 0.0555555556 | 0 | 0.0555555556 | 0.0138888889 | 0.0416666667 | -0.0555555556 | -0.0277777778 |
4 | 0.0833333333 | 0.0277777778 | 0.0555555556 | 0.0277777778 | 0.0555555556 | -0.0277777778 | -0.0277777778 |
5 | 0.1111111111 | 0.0444444444 | 0.0666666667 | 0.0444444444 | 0.0666666667 | -0.0222222222 | -0.0222222222 |
6 | 0.1388888889 | 0.0631313131 | 0.0757575758 | 0.0631313131 | 0.0757575758 | -0.0126262626 | -0.0126262626 |
7 | 0.1666666667 | 0.1666666667 | 0 | 0.1666666667 | 0 | 0.1666666667 | 0.1666666667 |
8 | 0.1388888889 | 0.0631313131 | 0.0757575758 | 0.0631313131 | 0.0757575758 | -0.0126262626 | -0.0126262626 |
9 | 0.1111111111 | 0.0444444444 | 0.0666666667 | 0.0444444444 | 0.0666666667 | -0.0222222222 | -0.0222222222 |
10 | 0.0833333333 | 0.0277777778 | 0.0555555556 | 0.0277777778 | 0.0555555556 | -0.0277777778 | -0.0277777778 |
11 | 0.0555555556 | 0.0555555556 | 0 | 0.0138888889 | 0.0416666667 | 0.0555555556 | -0.0277777778 |
12 | 0.0277777778 | 0 | 0.0277777778 | 0.0039682540 | 0.0238095238 | -0.0277777778 | -0.0198412698 |
The colums are, from left to right:
The point
The probability of rolling that point
The probability of winning with that point in regular craps
The probability of losing with that point in regular craps
The probability of winning with that point in crapless craps
The probability of losing with that point in crapless craps
The expected value of that point in regular craps
The expected value of that point in crapless craps
The sum of the EVs for regular craps = -1.4141%, and for crapless craps = -5.3824%
As you can see, the big drop is with the point of 11
Quote: unJonThe fun of crapsless is not the pass line bet. Play that for the min as you slam the fun bets like buying the extreme outside.
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I'm not sure for that is relevant to the discussion at hand. The question was about why the house edge is so much worse.
Quote: SkinnyTonyQuote: unJonThe fun of crapsless is not the pass line bet. Play that for the min as you slam the fun bets like buying the extreme outside.
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I'm not sure for that is relevant to the discussion at hand. The question was about why the house edge is so much worse.
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Given that someone has decided to accept playing the -EV of craps, a related question is in which way is crapless a “better” game. The pass line is worse, as others have said above.
On the other hand, crapsless has “better” bets than craps in that you can buy a 2, 3, 11 or 12. These bets are among the lowest house edge you can find in the casino. (Assuming vig is paid on wins only.)
Quote: unJonQuote: SkinnyTonyQuote: unJonThe fun of crapsless is not the pass line bet. Play that for the min as you slam the fun bets like buying the extreme outside.
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I'm not sure for that is relevant to the discussion at hand. The question was about why the house edge is so much worse.
link to original post
Given that someone has decided to accept playing the -EV of craps, a related question is in which way is crapless a “better” game. The pass line is worse, as others have said above.
On the other hand, crapsless has “better” bets than craps in that you can buy a 2, 3, 11 or 12. These bets are among the lowest house edge you can find in the casino. (Assuming vig is paid on wins only.)
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Sure, I'm not slamming crapless. I'm just answering the question on why the house edge is so much worse when intuitively it may seem better.
I think OP made a fair point. He made a mistake in his assumption that his added advantage on the 3 offset the disadvantage on the 11, but it's not an unreasonable mistake to make of you don't actually do the math or think about it too hard. So I think it was a good question.
Quote: CrapsmanThanks. In your 4th paragraph: How did you arrive at 9/7? To wit, 1:7 + 1/7 = 2/7. Where is the balance to arrive at 9:7? 2/8 + 2/8 = 4/8.
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3 and 11 are expected come up twice each in 36 rolls, and each wins 1/4 if the time. 2 and 12 come up once each, and each wins 1/7 of the time.
4*(1/4) + 2*(1/7) = 9/7.