BrooklynJake
• Posts: 24
Joined: Aug 30, 2011
August 30th, 2011 at 9:13:33 AM permalink
On one of the Wizard sites it said that that the house advantage for Black/Red bets in American roulette 5.26 percent. I believe this to be wrong. Here is my argument. First, the odds getting say black is (fail/succeed) = 20/18 = 10/9 in lowest terms. But the payout is even money; that is 9/9. So, the house advantage is [(10/9) - (9/9)]/(10/9) = (1/9)/(10/9) = 1/10 or 10 percent; not 5.26 percent. I just wanted to correct the error because this is not a very good bet.
RaleighCraps
• Posts: 2501
Joined: Feb 20, 2010
August 30th, 2011 at 9:22:57 AM permalink
I'm off to nuke a bag of popcorn. This should be good reading shortly. :-)
Always borrow money from a pessimist; They don't expect to get paid back ! Be yourself and speak your thoughts. Those who matter won't mind, and those that mind, don't matter!
thecesspit
• Posts: 5936
Joined: Apr 19, 2010
August 30th, 2011 at 9:25:14 AM permalink
That's not how you calculate house advantage, however.

The advantage is based on both winning and losing bets.
"Then you can admire the real gambler, who has neither eaten, slept, thought nor lived, he has so smarted under the scourge of his martingale, so suffered on the rack of his desire for a coup at trente-et-quarante" - Honore de Balzac, 1829
CrystalMath
• Posts: 1911
Joined: May 10, 2011
August 30th, 2011 at 9:38:30 AM permalink
5.26% is not a very good bet anyhow, but the Wizard is correct.

The house advantage is calculated by adding the winning bets and the losing bets, as stated above:

You will win 1 credit 18/38 of the time and you will lose one credit 20/38 of the time, so the house advantage is 18/38*1 + 20/38*(-1), which is 2/38, or 5.26%.
I heart Crystal Math.
BrooklynJake
• Posts: 24
Joined: Aug 30, 2011
August 30th, 2011 at 9:52:16 AM permalink
OK. 5.26% it is. Thanks for correcting me.
mustangsally
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August 30th, 2011 at 10:33:45 AM permalink
removed
silly
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FleaStiff
• Posts: 14484
Joined: Oct 19, 2009
August 30th, 2011 at 11:24:09 AM permalink
Quote: mustangsally

Another way to look at it is how much are you really being "short changed"?

I understand that "short changed" business. Its sort of the difference between the casino being a profit making business and the casino being some dumb jerk standing there and not getting paid a penny because they provide bets that are exactly fair. In roulette the concept might best be expressed as the Price of the Green. If there were no green, just all bets were half red and half black and the payout was 1:1, the casino could spin the wheel forever and it would all even out to zilch in profit. The Green exists to make the casino not care if red or black wins, because the casino is really making its money on the fact that the green gives the casino an edge.

The problem I have is that its the same 5.26 percent on these huge payout 35:1 and its also 5.26 percent on these tiny little 1:1 outside bets.

Now most of the time its going to be either Red or Black, you can be right or wrong several times in succession.
Yet inside numbers are many and whether you pick one number and stay with it or keep picking a new number each spin, you are still in a situation where it is overwhelmingly likely that you lose. This takes your bankroll down rapidly. And if you don't hit your 35:1 payout pretty darn quick, you are out of the game.

Yet its still 5.26 percent house edge.
statman
• Posts: 95
Joined: Sep 25, 2011
October 14th, 2011 at 2:40:06 AM permalink
A wheel was found in Oregon that was biased in favor of No. 0 so in the case of that particular wheel the house would have an even greater advantage. Further details in the thread "Simulating Murphy's Extreme Bias Wheel II."

I have never found the Wizard to be wrong except in two cases when he gave only an "estimate."
A fool is someone whose pencil wears out before its eraser does. - Marilyn Vos Savant
Switch
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Joined: Apr 29, 2010
October 14th, 2011 at 3:10:22 AM permalink
Quote: statman

A wheel was found in Oregon that was biased in favor of No. 0 so in the case of that particular wheel the house would have an even greater advantage. ... ...

Not necessarily. The edge, in roulette, is obtained by paying out 35/1 instead of 37/1 on all numbers. If a lot of the players were betting '0' then it would work against the house.
FleaStiff