Why Isn't Single-Zero Roulette -2.63%, Half of -5.26%?

I bought the new edition of Gambling 102 by the Wizard of Odds, Michael Shackleford. I liked the old edition (mostly to settle arguments over gambling math with my friends), but I wanted to check the new games covered in the book. But while I was leafing through it, I noticed that double-zero roulette has a 5.26% casino edge, while single-zero is 2.70%. Why wouldn't it be 2.63%, exactly half of 5.26%?

Glad you like Gambling 102 second edition. The new games in the book that you refer to, for everyone's benefit, are Crazy 4 Poker, Face Up Pai Gow Poker, High Card Flush, Mississippi Stud, Pai Gow (tiles), and Texas Hold 'em Bonus.

To answer your question, the difference is in the denominator in the equation that determines the edge.

Say you bet red in a game with two zeros. There are 36 numbers plus the zeros, making a total of 38 slots on the wheel. Of them, 18 (the reds) are winners and 20 (18 blacks and two zeros) are losers. That's a result of -2 units in 38 plays, yielding the equation -2/38 = -5.26%.

On a single-zero wheel, there are only 19 losers, meaning you lose only 1 unit, which would seem to indicate an edge of -1/38 = -2.63% (as you suggest).

However, removing the second zero leaves only 37 total slots, so the equation is -1/37 = 2.7%.

Why is the house advantage of single-zero roulette -2.7%, not 2.63%, half of the double-zero -5.26%?

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Dave Feb-03-2020

Triple zero

And the edge on the new triple zero game that’s been popping up all over? 3 / 39 = 7.69%!

Roulette math is amount the simplest of all casino math.

rokgpsman Feb-03-2020

Roulette

Roulette has been studied to death and there is no way to beat it but anyone can get lucky, just like on slots. Slot machines have a higher casino edge than roulette and if you only make the even-money bets (red/black, odd/even, etc) you have an even better chance of winning than you do on slots. The game is slow paced and can get boring for some players, but it can be some easy fun as a break from playing other games. Just don't expect to be ahead when you are done playing. And if you hit a lucky streak quit while ahead and enjoy the feeling for a while.

Kevin Lewis Feb-03-2020

A frontal lobotomy is cheaper than playing roulette

Another way to look at it is that the "green death zone" is not quite proportionately doubled when you add a second zero--it changes from 1/37 to 2/38, and the latter number is a bit less than twice the former.

Double zero roulette is one of the few stinky casino games that is so obviously bad, even the ploppies stay away (not that they don't plop their butts in front of slot machines, which are twice as bad).

Dave in Seattle. Feb-07-2020

Single zero

Just 2 casinos? Plaza and Paris?

Question of the Day - 03 February 2020

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