A friend who thinks he can "Beat Roulette"

[CheeseBeger]

For friend of mine explained to me an idea that he and his uncle thought of that they are going to try at a casino. I immediately thought there must be something wrong with this, but I need help proving it wrong. They want to start with a bet on either red or black, and if they win they will "pocket" the money and start again. If they loose ($1) they will double the next bet to two dollars in an attempt to get to 0 and start over. They will continue this process until they eventually get back positive and then pocket that money. Please explain to him why this won't work.

[slickpoppa]

This system is called a martingale. For an explanation of why it won't work, read this site:
web page

[bholdr]

in BJ, it's called martingale.
with apologies to Elric from bonuswhores:

"Sweet I think I will use this Martingale system... I am going to quit my job and just start grinding out the big bucks!!!!

Bet $1 lose
Bet $2 lose
Bet $4 lose
Bet $8 lose
Bet $16 lose
Bet $32 lose
Bet $64 lose
Bet $128 lose
Bet $256 lose
Bet $512 lose
Bet $1024 lose <==== Start into my Poker Bankroll
Bet $2048 lose <==== Borrow from my checking account
Bet $4096 lose <==== Cash advance on my VISA card
Bet $8192 lose <==== Sell my car
Bet $16384 lose <=== 2nd mortgage on my trailer home
Bet $32768 lose <=== Borrow from the kids college fund
Bet $65536 lose <=== Call mom & dad for an emergency loan

err "Dad I need to borrow $65536... I have the sure fire way of making money that is FOOL proof. All I need is this chunk of change so I can win my $1 back."

Opps I am totally tapped out while I was trying to win a $1"

[kyro]

I guess theoretically if they had an infinite bankroll it would work. But basically they're risking a crapload of money to win a buck here and there.

[Freudian]

If we assume infinite bankroll, we must also assume infinite losing streak.

And a non-theoretical point: Most casinos have max bets, so you are not allowed all that many tries, even with a big bankroll.

[niin]

This 'system' is well known, and it's well known that it doesn't really work. Plus, betting on red/black is not an even money bet; it's even money payout, but the odds are not 1:1 to hit your color, due to the 0 or 00 on the wheel.

[stigmata]

Using this system you can change the payout structure, whilst leaving the underlying odds the same.

If you have a deep enough bankroll, you are unlikely to start off on a really bad run. Therefore, you could use it have a good chance of winning a small amount of money, at the cost of a small chance of losing everything.

Its like betting on very short odds on sport. I remember hearing about a guy who had placed a £20,000 bet on a soccer game with 10 minutes left.

England were 2-0 up, and he bet that England would win. He stood to make £200 profit. England let in two goals in the last ten minutes, and he lost the lot.

[bogey]

dont forget casinos have max bets

[kyro]

good point about the max bets. i don't think you necessarily have to assume infinite losing streak, though. it's still a worthless theory though. If you have a bankroll big enough, say 100K, you're going to be able to make $1 every 5 or 6 rolls on average I'm guessing.

[Oski]

[ QUOTE ]
Using this system you can change the payout structure, whilst leaving the underlying odds the same.

If you have a deep enough bankroll, you are unlikely to start off on a really bad run. Therefore, you could use it have a good chance of winning a small amount of money, at the cost of a small chance of losing everything.

Its like betting on very short odds on sport. I remember hearing about a guy who had placed a £20,000 bet on a soccer game with 10 minutes left.

England were 2-0 up, and he bet that England would win. He stood to make £200 profit. England let in two goals in the last ten minutes, and he lost the lot.

[/ QUOTE ]

3 goals: 2 in the last 45 seconds. It happened this past June v. France.

I lost 10 bucks on that one. (had England on money line)