zoomie: When should a non-AP know when to quit?

[zoomie]

Let's say a Martian lands here and starts to play BJ (or SP21) in a casino. He does not know whether the game is 50/50 or if there is an edge for house or for players. He uses perfect basic strategy, flat bets, keeps perfect records of number of hands played and outcomes. Unlike me he has excellent knowledge of the mathematics of hypothesis testing. Given the standard deviation of BJ (or the slightly higher SD for SP21), how many hands would the Martian need to play to test the hypothesis that the game is 50/50?

What motivates this question is observing such abysmal SP21 play. Just when I think I've seen everything, a guy surrenders soft 13 against a 5 (true) or whatever. Between poor play and the huge popularity of the Match bet (HE 3%), the ploppies must be playing at minus 2 - 3% anyway. Yet they keep playing. I'm wondering if, to be charitable, the inherent volatility of the game is such that even an intelligent, "scientific" player would have to lose over a very long run before realizing that it is hopeless.

[Wes]

I'm wondering if, to be charitable, the inherent volatility of the game is such that even an intelligent, "scientific" player would have to lose over a very long run before realizing that it is hopeless

{{the inherent volatility of the game}}

Bingo! I think you hit the nail on the head.

Wes

[Don Schlesinger]

You're really asking two very different questions. People ALREADY know that the games they are playing are negative expectation. They play anyway, because they pay a price for entertainment. The SP21 ploppies don't care they they give away 2-3%. That's peanuts compared to what other players give away at other games (think Keno, Big Six, American roulette, etc.).

Now, your other question is, simply, how many hands do we need to play before we realize that our losses are due to negative expectation, rather than to "bad luck" at an inherently even-money game? The answer to that depends, of course, on the game you're playing (rules, for BJ), and how "sure" you want to be (how many standard deviations) of your conclusion.

If you want some sample math, let me know. If you already understand and can do the math yourself, well, then, good!

Don

[Brick]

This question is sorta the same but on different terms,suppose a BS player knows his ev is -1% and after about 500 or so hours he's losing $10,000 when ev says his negative expectation is $5,000.

Would it be a nightmare if he assumes he'll win back some or all of the $5,000 sooner or later?

[Don Schlesinger]

> This question is sorta the same but on different
> terms,suppose a BS player knows his ev is -1% and
> after about 500 or so hours he's losing $10,000 when
> ev says his negative expectation is $5,000.

If the e.v. is -$5,000, then, at -1%, he has wagered $500,000. If he plays 500 hours at 100 hands/hour, that's 50,000 hands, so, let's say he's flat-betting $10 a hand.

The standard deviation for a hand of blackjack is about 1.15 units, or, in this case, $11.50 a hand. The square root of 50,000 is 223, and 223 x $11.50 is $2,571. So, losing $10,000, instead of $5,000 is to be losing $5,000/$2,571 = 1.94 s.d.s, which happens with probability 2.6%, or, roughly, 1 in 38. such a loss would be unfortunate but surely not impossible.

> Would it be a nightmare

Do you mean "would it be dreaming?"? Using "nightmare," in this context doesn't make sense. A nightmare is something bad, and winning back $5,000 is something good. Maybe you meant "pipe dream"?

> if he assumes he'll win back
> some or all of the $5,000 sooner or later?

Well, of course it's possible to win some of it back. I wouldn't count on winning it all back, at $10 a hand, though. Considerably harder task than losing it! Like swimming upstream.

Don

[Brick]

>Would it be a nightmare if he assumes he'll win back some or all of the $5,000 sooner or later?<

From the players perspective,I think its indeed a pipe dream if they assume winning back $5000 at 10 dollars a hand, is within reach.

From my perspective, what I mean by nightmare is ...the ploppy plays on and on(say another 500 hours)assuming he'll win about half his money that he previously lost, or thinking his -ev,standard deviation,etc. will somehow balance out, only to lose a couple more thousand,then wondering what went wrong.

Suppose this ploppy was using chips of a much higher value, then you can easily see how a nightmare could occur.