Probablity of Craps Don't Pass Bet
March 1st, 2011 at 6:40:04 PM
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I've read through a lot of the Wizard of Odds site & lots of posts here. I understand probability & all the math involved. I understand the computations involved with figuring the 1.4% house advantage on the Don't Pass/Don't Come bet. But.....
Here's how I look at it: When I'm betting DP/DC there are only 8 of 36 possible come out rolls that hurt me. So, 8 losers, 1 push, 3 winners, and 24 points. To me that means USUALLY I will survive the come out roll. After that, when I'm behind a point I will USUALLY win because there are always more ways to roll a 7 than the point I'm behind.
If I survive the come out roll more often than not, and I win behind a number more often than not, how do I not have the advantage over the house?
Thanks for your replies!
Here's how I look at it: When I'm betting DP/DC there are only 8 of 36 possible come out rolls that hurt me. So, 8 losers, 1 push, 3 winners, and 24 points. To me that means USUALLY I will survive the come out roll. After that, when I'm behind a point I will USUALLY win because there are always more ways to roll a 7 than the point I'm behind.
If I survive the come out roll more often than not, and I win behind a number more often than not, how do I not have the advantage over the house?
Thanks for your replies!
March 1st, 2011 at 6:52:22 PM
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That "push" on 12 is what gives the house an edge.
Its fun to play the Dark Side but sometimes tables are simply lucky and all those Right Way Bettors are making the money!
Its only AFTER the come-out roll that the SEVEN makes the Don't players happy. That is why it is foolish to declare No Action on a Dont bet that would otherwise travel to the 6 or 8. Dealers will suggest you declare No Action but dealers don't always know the math.
That "hurdle" for the Dont Player is that next roll: 7 will knock his bet down and 7 is more likely than anything else.
Its fun to play the Dark Side but sometimes tables are simply lucky and all those Right Way Bettors are making the money!
Its only AFTER the come-out roll that the SEVEN makes the Don't players happy. That is why it is foolish to declare No Action on a Dont bet that would otherwise travel to the 6 or 8. Dealers will suggest you declare No Action but dealers don't always know the math.
That "hurdle" for the Dont Player is that next roll: 7 will knock his bet down and 7 is more likely than anything else.
March 1st, 2011 at 7:15:41 PM
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Yes, the "hurdle" is surviving the come out roll, avoiding the 7 or 11. Once I'm behind a point I NEVER pull my bet down, even behind 6 or 8. The odds are in my favor at that point. I've cleared the hurdle. Why would I want to pull my bet down & try to make it over the hurdle again?
And yes, I've seen the dealers who ask if I want to travel to the 6/8 & look at me funny when I say, "Yes!". You know, they say they want you to win but I'm not sure if it's just a facade.
My question remains. MOST of the time I will clear the hurdle, 27 out of 36 tries. The occasional push doesn't hurt me, just means it's time to try again. Once I'm behind a point I have to get "unlucky" to lose. MOST of the time behind a point I will win. So the question is, why am I not considered as having an advantage over the house when I bet the DP/DC?
And yes, I've seen the dealers who ask if I want to travel to the 6/8 & look at me funny when I say, "Yes!". You know, they say they want you to win but I'm not sure if it's just a facade.
My question remains. MOST of the time I will clear the hurdle, 27 out of 36 tries. The occasional push doesn't hurt me, just means it's time to try again. Once I'm behind a point I have to get "unlucky" to lose. MOST of the time behind a point I will win. So the question is, why am I not considered as having an advantage over the house when I bet the DP/DC?
March 1st, 2011 at 7:33:07 PM
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Which is why you have to lay more to win less. The luck is on your side.Quote: bbdsanMy question remains. MOST of the time I will clear the hurdle, 27 out of 36 tries. The occasional push doesn't hurt me, just means it's time to try again. Once I'm behind a point I have to get "unlucky" to lose. MOST of the time behind a point I will win.
You're a significant dog on the come-out. Watch how many times the 7 or 11 rolls and the dealer takes your bet. It's a lot.Quote:So the question is, why am I not considered as having an advantage over the house when I bet the DP/DC?
"Dice, verily, are armed with goads and driving-hooks, deceiving and tormenting, causing grievous woe." -Rig Veda 10.34.4
March 1st, 2011 at 7:56:28 PM
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I'm not a dog on the come out though. Only 8 of 36 possible rolls hurt me. So 77.8% of the time I won't lose on the come out. 77.8% of my come out rolls will either be a push (12), a win (2 or 3), or put me behind a point (4, 5, 6, 8, 9 or 10). 66.7% of my come out rolls will be a point. Once I'm behind a point, I'm a favorite to win.
March 1st, 2011 at 8:04:40 PM
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Quote: bbdsan
My question remains. MOST of the time I will clear the hurdle, 27 out of 36 tries. The occasional push doesn't hurt me, just means it's time to try again. Once I'm behind a point I have to get "unlucky" to lose. MOST of the time behind a point I will win. So the question is, why am I not considered as having an advantage over the house when I bet the DP/DC?
You are correct.
Now we need to see what happens to those 27 times.
The Wizard over at WoO has a don't pass table but is is a short version.
Here are all the ways to win and lose.
I did not use for 36 since when you start dividing one gets many fractions and we only want to work with integers.
If you do not understand this, let us see who else tries.
| Event | ways |
|---|---|
| comeout win | 165 |
| comeout loss | 440 |
| push | 55 |
| win on 6 | 150 |
| loss on 6 | 125 |
| win on 8 | 150 |
| loss on 8 | 125 |
| win on 5 | 132 |
| loss on 5 | 88 |
| win on 9 | 132 |
| loss on 9 | 88 |
| win on 4 | 110 |
| loss on 4 | 55 |
| win on 10 | 110 |
| loss on 10 | 55 |
| total | 1980 |
949 ways to win
976 ways to lose.
Just from that we can see a difference of 27. -27/1925 = -0.014025974
And counting the pushes -27/1980 = - 0.013636364
So, one must weigh all the ways to win verses all the ways to lose.
Now if there was no Bar12 or a push
Then
ways to win 1004
ways to lose 976
a difference of 28
28/1980 = 0.014141414 a players advantage
FYI: For 36
Event ways
comeout win 3
comeout loss 8
push 1
win on 6 2.727272727
loss on 6 2.272727273
win on 8 2.727272727
loss on 8 2.272727273
win on 5 2.4
loss on 5 1.6
win on 9 2.4
loss on 9 1.6
win on 4 2
loss on 4 1
win on 10 2
loss on 10 1
total 36
The numbers are multiplied by 55 to produce the 1980 chart above
March 1st, 2011 at 8:10:51 PM
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Whoosh. It's a little more complicated than that. You won't ALWAYS win against the point once you travel. You're only a slight favorite on those points. That slight favoritism is balanced by the slight disadvantage on the come-out.Quote: bbdsanI'm not a dog on the come out though. Only 8 of 36 possible rolls hurt me. So 77.8% of the time I won't lose on the come out. 77.8% of my come out rolls will either be a push (12), a win (2 or 3), or put me behind a point (4, 5, 6, 8, 9 or 10). 66.7% of my come out rolls will be a point. Once I'm behind a point, I'm a favorite to win.
There is a mathematical model for this called the "perfect 1980." Search some of the craps sections on this board or read goatcabin's posts/blog. (Edit: I see guido has helpfully posted it above).
"Dice, verily, are armed with goads and driving-hooks, deceiving and tormenting, causing grievous woe." -Rig Veda 10.34.4
March 1st, 2011 at 10:14:48 PM
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Got it. Took me a little while to understand the win on X and loss on X numbers. For those readers struggling like I was:
In 36 rolls there are:
5 ways to roll a 6
6 ways to win behind the 6
5 ways to lose behind the 6
win on 6 = 5 * 6/11 = 2.727272....
loss on 6 = 5 * 5/11 = 2.272727....
So out of 36 rolls, your point will be 6 five times, you'll win 2.727272... times and lose 2.272727.... times.
Then to make that table he just multiplied all the "ways" by 55 so they come out as integers.
Thanks guido111!
In 36 rolls there are:
5 ways to roll a 6
6 ways to win behind the 6
5 ways to lose behind the 6
win on 6 = 5 * 6/11 = 2.727272....
loss on 6 = 5 * 5/11 = 2.272727....
So out of 36 rolls, your point will be 6 five times, you'll win 2.727272... times and lose 2.272727.... times.
Then to make that table he just multiplied all the "ways" by 55 so they come out as integers.
Thanks guido111!
March 1st, 2011 at 10:53:37 PM
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Quote: bbdsanGot it. Took me a little while to understand the win on X and loss on X numbers. For those readers struggling like I was:
In 36 rolls there are:
5 ways to roll a 6
6 ways to win behind the 6
5 ways to lose behind the 6
win on 6 = 5 * 6/11 = 2.727272....
loss on 6 = 5 * 5/11 = 2.272727....
So out of 36 rolls, your point will be 6 five times, you'll win 2.727272... times and lose 2.272727.... times.
Then to make that table he just multiplied all the "ways" by 55 so they come out as integers.
Thanks guido111!
Thank you.
Excellent work yourself!
March 2nd, 2011 at 12:11:40 PM
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I was thinking about it some more & figured out another flaw (besides the mathematical flaw discussed above) in my original thinking. My original thinking was, "I'm a favorite to survive the come out (27/36), and I'm a favorite to win behind a point, therefore I must be a favorite OVERALL (I have the advantage over the house)." The "Grandma English" flaw is this; When I survive the come out I (usually) don't win any money. I just move on to a 2nd trial (being behind a point), which is not a sure thing. As teddys said, "That slight favoritism is balanced by the slight disadvantage on the come-out."
March 2nd, 2011 at 1:45:18 PM
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The come out roll is a "win, lose or else 'qualify for the bonus round'" situation. The DontPass bettor is like any other bettor: he has to remember that even if he qualifies for the 'bonus round' he may not win it.
