whodat
Joined: May 11, 2015
• Posts: 104
May 11th, 2015 at 8:41:20 PM permalink
I have studied the house edge calculations for the pass and come bets at the wizard of odds site extensively. The house edge of 1.4% for each bet is based on winning when a 7 or 11 hits, losing when a 2,3,or 12 hits AND the resolution of an established point. This works the same way when someone comes to the crap table and put money on the come bet when a point is established. HOWEVER, what about when a player has a pass line bet, a point is rolled, and he now wants to place a come bet (this is the strategy many have used--pass line with odds and come bets with odds). At this point, the come bet may win on a 7 but the pass line will lose. The bettor puts down a come bet but does not want a 7 to be rolled. How does this affect the house edge calculation on the come bet because you now win on and 11 or the ON point, push (lose pass line but win come bet) on a 7, and lose on 2,3,12?
The current house edge calculation is 8/36 + 9648/35640 or 244/495 (to win) versus 251/495 (to lose)
The complicated fraction (9648/35640) is based on rolling a point and rerolling that point before rolling a 7.
Can the wizard or anyone with savvy in probability answer my question?

Whodat
rdw4potus
Joined: Mar 11, 2010
• Posts: 7035
May 11th, 2015 at 8:45:39 PM permalink
I followed you right up to the point where you applied the passline 7 loss to the come bet's house edge. Are you sure you want to do that? I don't think this situation affects the house edge on either the come bet or on the passline bet. They both exist, separately, and they both have separate house edges and different win conditions.
"So as the clock ticked and the day passed, opportunity met preparation, and luck happened." - Maurice Clarett
MathExtremist
Joined: Aug 31, 2010
• Posts: 6526
May 11th, 2015 at 9:08:33 PM permalink
You could determine the outcome distribution of a combined "pass + first come bet when the pass wasn't natural" bet, but it wouldn't serve any purpose other than to gauge the variance of that combination. The pass and come bets are independent wagers and the house edge is identical between them. The only outcome that resolves both wagers at the same time is a 7, and depending on the state of the come bet that could either be a pass loss + come win or pass loss + come loss. Of course, it's also possible to resolve a pass bet and have a come bet still working.

Bottom line, it's easiest to deal with each bet independently.
"In my own case, when it seemed to me after a long illness that death was close at hand, I found no little solace in playing constantly at dice." -- Girolamo Cardano, 1563
mustangsally
Joined: Mar 29, 2011
• Posts: 2463
May 11th, 2015 at 9:08:37 PM permalink
nice little question
Quote: whodat

How does this affect the house edge calculation on the come bet

i say
it does not "affect the house edge calculation on the come bet"

now you are trying to figure out after one bet has started its journey
but not resolved and another starts.
the come bet knows nothing about the pass line bet as does the pass line bet knows nothing about the come bet as the dice do not even know about either bets.

the bets are independent and the house edge as you calculated is every possible path that can be taken to a resolution
BEFORE the dice are rolled and considering every possible roll after that that results in a bet being resolved.

plus, when i simulated this a few years ago, it showed no difference in the house edge
just the ev changed due to the fact that more than 1 bet could be resolved per pass line decision

now i have seen a craps roll while a come bet sat in the come box and thought the dealer did not pick it up as a losing bet
that can change the house edge for the come bet (it was not my come bet)

maybe some one will bring some math to the plate for you
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richbailey86
Joined: May 8, 2014
• Posts: 325
May 12th, 2015 at 3:40:55 AM permalink
Very interesting i was thinking about the same thing

I was researching 'safer' bets and how to stay at the table longer

One thing i found was betting pass line and when a point is made place a come bet to block a 7

Slowly but surely i am learning this game

Of course after the come bet moves to a number you can still 7 out but its still interesting

As another member here told me if that 3rd roll is a 7 then you lose pass line plus you lose on the number where the come chips went
An idea whose time has come cannot be stopped by any army or any government. – Ron Paul
NokTang
Joined: Aug 15, 2011
• Posts: 1314
May 12th, 2015 at 5:04:31 AM permalink
Quote: mustangsally

now i have seen a craps roll while a come bet sat in the come box and thought the dealer did not pick it up as a losing bet
that can change the house edge for the come bet (it was not my come bet)

That was of course, a dealer not paying attention and without boxman support. How to take advantage of such a situation remains the big question. It won't happen again in most cases and/or if you were to make the come bet a larger amount in an effort to take advantage of their inability to keep up with the game. It isn't cheating IMHO to take advantage of a dealers mistake. I've done it many times on a busy table when betting the don't pass. I've been paid on a pass line winner more times than I can count and usually leave the table after it happens. I'm not cheating, just taking advantage of gifts or comps given to me. Call me a dirtbag if you wish, but trust me, taking \$500.usd from Donald Trump at the Taj Mahal didn't make me cry or lose sleep.
whodat
Joined: May 11, 2015
• Posts: 104
May 12th, 2015 at 7:47:17 AM permalink
Thanks for all the responses. I understand that if you were to look at the events as independent then the HE is 1.4 regardless. Unfortunately they are somewhat dependent in my mind because the roll on the come bet can affect the outcome of the pass bet + odds. Logically without looking at independent bets, when you place a come bet after a pass line bet has been in place you are really hoping that the 7 does not roll because you would win your come bet and lose your pass line + odds bet for a negative outcome. So in actuality, you want either an 11 or a point number (2 + 3 + 4 + 5 + 5 + 4 + 3) or 26/36. The advantage of a pass line or a come bet lies in the natural being rolled on the first roll. After that it has a horrible EV. If you place a come bet hoping that a 7 would not be rolled it defeats the purpose of the advantage. Makes me rethink whether I want to just play pass line + odds as opposed to establishing multiple points.
mustangsally
Joined: Mar 29, 2011
• Posts: 2463
May 12th, 2015 at 8:16:18 AM permalink
Quote: whodat

Thanks for all the responses.
I understand that if you were to look at the events as independent then the HE is 1.4 regardless. Unfortunately they are somewhat dependent

no
you understand wrong
in other words
not correct

they are either dependent or independent events (bets)
never somewhat
math is not like that

the bets are independent events by their definition
the house edge will never change
=========================
what changes when making more than one bet will be the expected value of X bets and the variance
but you ask about the house edge and that can never change

it is that simple

I would pay you real cash to
simulate this and you will see who may be right
or

you can do a thought experiment right now

I make 1 pass line bet
the roll = 6
you make a come bet
the roll = 8
the Wizard makes a come bet
the roll = 9

3 bets are made in total and the house edge has not changed for one bet

what is the difference if 3 bets are made from 3 players or 3 bets are made by one player
same house edge
different ev and variance is the answer

again, i say
they are not "somewhat dependent" events
even if you think they are

and if you feel awful thinking about them because

there are many other and better bets to be made, in my opinion
next
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surrender88s
Joined: Jun 23, 2013
• Posts: 291
May 12th, 2015 at 8:39:05 AM permalink
Trying to give a simple answer, you can never combine any number of +HE bets to get a -HE bet. You can play with variance and payouts based on your total bet, but you are never changing the odds on the individual bets. But there are different sets of odds based on whether or not the come point is established.
"Rule No.1: Never lose money. Rule No.2: Never forget rule No.1." -Warren Buffett on risk/return
charliepatrick
Joined: Jun 17, 2011