On 12/30/23 3:50 PM, Rich D wrote:
"I am playing a fair even money game flipping coins.
My opponent cannot quit. I intend to quit any time I
get one bet ahead. Do I have an advantage?"
Bard:
Yes, you do have an advantage in this scenario. Here's why:
Limited downside: Since you are guaranteed to quit after winning
one bet, your maximum possible loss is limited to losing your initial bet. Unlimited upside: Your potential winnings, on the other hand, are unlimited. As long as you keep winning individual flips, you can
keep doubling your money.
Probability still in your favor: Each coin flip is still a 50/50 chance
of winning, favoring you just like even-money odds suggest. So,
statistically speaking, you're more likely to win any individual flip
than lose it.
--
Rich
The one issue is that if you do not have an unlimited bankroll, you may
be forced to quit due to running out of money to make bets, with a loss
of your full bankroll. This must be taken into account to compute your advantage. Of course, if you have unlimited funds, you can reduce the
chance of losses to effectively zero, but it also means that you
winnings, which will be just 1 bet, are an infintesimal fraction of your bankroll.
You need to do the maths to see if the small chance of losing everything
(or you max losing you are willing to lose) out ways the large chance of winning the single bet value.
Note, your winnings are limited to a single bet, as your strategy is to
quit after a net winning of just 1 bet. Yes, you might be able to play
again, but that reinstalls the chance of total loss, even of what you
have just won.
I seem to remember, that the maths work out that if you have an N bet
bankroll, and a 50-50 game, there is a 1/(N+1) chance of losing N net
bets before being up 1 bet (and thus an N/(N+1) chance of winning) so
your "advantage"" is 1 * N/(N+1) - N * 1/(N+1) = N(N+1) - N/(N+1) = 0
Thus, as long as you have a finite bankroll, you have no advantage with
this stratagy, which has been used MANY times (when the odds were
slightly against you) to the demise of much money. The Casinos do not
mind this sort of stratagy, as the small wins provide the dopamine hit
to make the people try again, and the house gets to eventually keep the
money.
--- SoupGate-Win32 v1.05
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