Thursday, January 6, 2011

Always Bet on Black.

In Diamonds are Forever, James Bond bets on 17 Black. It is, of course, a European roulette wheel, with 18 red, 18 black and 1 green.

What is the probability of his getting the ball to drop in 17 Black twice in a row?

1/37 * 1/37, which equals 0.07%

 How cool is that?


  1. Of course the probability of hitting 23 red and then 23 red is also 0.07%.

    Not as cool.

    And with a 35:1 payout (is that right?), what's the expected value of each bet? -1/37 or -2.70% ... far better than the Vegas wheel (which my seniors just calculated to their surprise on Thursday... worse than -5%)


  2. Yet still one of the fairest games in the place.

    Not like Keno. Bleah.

  3. Poker, which I can't play, allows good players to win. That's one of a kind in a casino.

  4. I don't consider poker to be a purely probabilistic gambling game. The players, bluff, and cash source are far too important and play a higher role than strict probability.

    For evidence, check the World Series of Poker: Same faces every year. That's not coincidence.

    For just "Me against the probabilities" type of betting, roulette and the pass/don't pass bets are some of the fairest yet legal bets around. A house edge of 1% - 3% is pretty good really.

    If you know how (really know and practice, not just think you do) to count cards in blackjack, you can approach even odds or swing them in your favor. It just sucks getting caught.

  5. I should expand on the poker thing. One edge that some players have is the casino's pocketbook. The casinos will sometimes have a player at the table who is on their payroll and is using house money. It's really tough to bluff someone with nothing to lose -- the casinos deny it but do it anyway.

    The other edge they have is practice. Like a lot of things that Gladwell 10,000 hour rule holds. You gradually, and subconsciously, develop a sense of what every player is holding. Fidgets, sighs, twitches, attitude and a myriad of other tells -- comes with experience. The top players do this consciously and gain an even bigger advantage.

    Know when to hold, know when to fold, and walk out when you're up a bundle. It's more like a a bar fight than an exercise in probability.