Risk of Ruin?

I am a somewhat experienced player having BS down and can count using KO. Once a week, myself and a co-worker go to a local casino to play some BJ on our lunch hour.

Against my advice, he has been using his "system" in which he just doubles his bets if he loses, starting at a $10 minimum. So far in 4 trips, he is up $225 but I keep telling him that sooner or later he will lose his shirt. At this casino, they use CSM's so I cannot count and gain an advantage but I go for fun and also to see my friend's outcome.

I'd like to see if anyone can give me stats on how long my co-worker will go until he hits the $500 table minimum? I calculate that is 6 losing bets in a row (10,20,40,80,160,320) and have read the odds in that happening are 1 in 80. Is this correct? Can anyone run this threw a simulator?

Thanks

Is he prepared to go all the way to the max? zg

I think it would just be something like (.53^6).

The chance that he will lose 6 in a row and bust is .53^6 = .0222

or 1 out of 45.12 series.

I think the chances of him winning a given series is 1-.0222= 97.8 percent


He only needs to win 32 series to double his bankroll.

.978^32= 48.8 percent chance of doubling his bankroll.

I find it odd that when I do this I get a higher percent chance of doubling your bankroll then if you bet it all on one had which would be 47%. I did not have rounding errors.

Actually you would have a higher chance of doubling your bankroll because I did not take into account blackjacks and doubles and splits.

You couldn't break the 50% barrier could you?

This must be wrong because I know you can't overcome the house edge but I don't know why it is wrong.

If you were playing European Roulette then they have a 18/37 = a 51.35 percent chance of losing.

.5135^6 = .0183.

1 - .0183 = 98.2 percent chance of winning a given series.

You only need to win 24 series to double your bankroll.

10-20-40-80-120-240

.982^24 = a 64 percent chance of doubling your bankroll.

That cannot be right.

I already answered a similar question like this to you already privately, but I will answer this one here as well.

First of all, the odds of losing is 19/37, not 18/37. But you did have the correct number of .5135. So 0.5135^6=.0183. That means that you will lose one out of every 54.64 attempts.

Now, I should point out that your martingale numbers got off a little bit there. You went from 80 to 120, which isn't a true martingale, which I am assuming you were trying to have in the problem. So the new numbers are,
10-20-40-80-160-320.

Now lets assume we play exactly 54.64 spins just for the example. We will lose one of them, giving us a net loss of 630. We will win 53.64 of them netting us a win of 536.40. So after 54.64 attempts we should expect to lose (536.40-630)=93.60 LOSS. That is not overcoming the house edge!

About the odds of doubling your bankroll. That would then be .982^32=56%. In your previous post you said "You couldn't break the 50% barrier could you?". Just because you have more than a 50 percent chance of doubling DOESN'T mean you are overcoming the house edge. To perform this martingale correctly you need 630 dollars. So that means you have a better chance (56%) at winning 320, than you do losing the entire 630. So you will double your bank more often than you go broke, but when you do lose you will lose quite a bit more than when you win. So even though you have a greater than 50% chance of doubling your bank, it doesn't mean you are overcoming the house edge!

I believe he'll bet up to his winnings, so with $225 won now, he would bet $10, $20, $40, $80 and then quit if he lost. If he ever reaches total winnings of $320, he would then bet the next one, which is $160 and quit if he loses that hand.

I keep telling him it is only a matter of time....

It shouldn't take long using the martingale starting from 10 dollars! Try to get him to stop, but if you can't, he will learn way one or another...

NO. Don't give him anymore negatives - cheer him on! Really I mean it. zg

I have a free online BJ Progression System Tester at http://www.qfit.com/blackjack-progression-tester.htm

Very useful! :devil: Thanks Norm

What would your friend do on his max bet when he encounters split situations coupled with double down opportunities? It's not uncommon to have 3, 4, 5 or more bets out on one hand due to this, would he deviate from BS? Good luck standing on his 88 vs 7!

That's probably what I would do, considering I am a "high Mach". :devil:

I am going to cheer my co-worker on!

He said he went to a casino this past weekend and hit the $80 (4 loses in a row) twice and luckily won both times. I'll keep you all posted on his success or demise....