Math confirmation wanted for a casino dispute...

[Matt Rain]

Huge variance in blackjack. The player can go on a real hot streak and the computer has to call in a virtual cooler to stop him bringing down the house.

Haha.

So how many online Blackjack players are there out there? 10,000? How many hands may they play a year on average? 10,000? So how many (how often) will bump into a loss of 250 units over 3500 hands? Trust me enough to have at least one now knock on Justin7's door that is playing at a A+++ book.

That was my first thought as well. Tons of players who can easily autoplay a couple thousand hands per hour - crazy runs happen, and I've got screenshots of much weirder stuff.

[Ganchrow]

that even Ganchrow misses the main point really starts to worry me.

This corresponds to a single-tailed p-value of about 0.031%.
I am simply assuming that this is right. Not in a mood to double check it all. So on a stretch of 3500 hands there is a 1/3000 chance that one will lose 250 units. So how many online Blackjack players are there out there? 10,000? How many hands may they play a year on average? 10,000? So how many (how often) will bump into a loss of 250 units over 3500 hands?

I was merely answering the OP's initial question in reference to a single given player as it that about which he was quite specifically asking. To wit:

A player plays 3531 hands of Blackjack, betting a fixed amount on each hand. Assume the house edge is 0.5%, and standard Las Vegas strip rules for everything (I'm slightly overestimating the house edge).

What are the odds that the player suffer a net loss of 250 bets in this period, assuming he plays perfect basic strategy, and there is a shuffle after every hand?

The impetus behind my answer now clarified, I can further assure you I'm quite aware of the necessity of adjusting for selection bias and I believe I've made several posts on this forum that so demonstrate means of doing so as well as the importance thereof. Continuing along these lines is left a straightforward exercise for the moderately statistically adept reader.

[pico]

taco is right. i think most online casinos has virtual cooler at owner's discretion.

[Justin7]

FYI, the software under investigation is ThrillX.

[WileOut]

That is not variance, but rather expected return. See this for more info: http://en.wikipedia.org/wiki/Central_moment



Justin,

I suck at math but a claim of 6% here is absurd just intuitively. Your conclusion does not surprise me, although perhaps you are slightly underestimating the variance by using 50/50.

If the expected return is less, the variance is going to be less, all other variables being equal.

http://www.econmodel.com/classic/riskreturn.htm

The two have a positive correlation. That correlation may be large or small but it does exist.

Its the same concept with your expected return and your risk (variance/standard deviation) in your portfolio. The greater you want your expected return, the greater risk you are going to have to take on.

[MonkeyF0cker]

That Justin7 has no idea what he is talking about is not new to me, but that even Ganchrow misses the main point really starts to worry me.

This corresponds to a single-tailed p-value of about 0.031%.
I am simply assuming that this is right. Not in a mood to double check it all. So on a stretch of 3500 hands there is a 1/3000 chance that one will lose 250 units. So how many online Blackjack players are there out there? 10,000? How many hands may they play a year on average? 10,000? So how many (how often) will bump into a loss of 250 units over 3500 hands? Trust me enough to have at least one now knock on Justin7's door that is playing at a A+++ book.

No offense, acw, but I think you're the one missing the point actually...

Thanks for the link. This suggests it is about 1 in 10,000. This is a far cry from the 6% chance the book quoted.

I'll give more facts later, but I need to keep exploring this. This one could get interesting.

[donjuan]

If the expected return is less, the variance is going to be less, all other variables being equal.

http://www.econmodel.com/classic/riskreturn.htm

The two have a positive correlation. That correlation may be large or small but it does exist.

Its the same concept with your expected return and your risk (variance/standard deviation) in your portfolio. The greater you want your expected return, the greater risk you are going to have to take on.

This simply isn't true. It occurs in the finance world due to the risk premium (risk free rate + risk premium= exp return) not because of some inherent relationship between expected return and variance/s.d. Perhaps you could convolute some risk premium for playing at a book like Sportsbook.com where you might have a higher exp return and also a higher risk of having your funds confiscated but that is pretty much irrelevant to the original topic.

[WileOut]

This simply isn't true. It occurs in the finance world due to the risk premium (risk free rate + risk premium= exp return) not because of some inherent relationship between expected return and variance/s.d. Perhaps you could convolute some risk premium for playing at a book like Sportsbook.com where you might have a higher exp return and also a higher risk of having your funds confiscated but that is pretty much irrelevant to the original topic.

There is a relationship between expected return and variance in the finance world. If you want a small expected return with low variance then you go bonds. If you want a higher expected return with medium variance you go large cap stocks. If you want even higher expected return with high variance (risk of negative return) then you go small cap/growth stocks. You can't say, ok I want a high expected return with very low risk. Unless you get inside tips or something you can't acheive this.

This is a fact.

Now if this isn't true for casino games, it would shock me. The higher expected return the house wants, the more the player is going to risk losing every time they play. That is just common sense.

Sorry if this is a little off topic. I was just trying to put a .05% expected return into laymans terms (house wins 1 hand more every 200 hands) and donny jumped on it.

[tacomax]

Now if this isn't true for casino games, it would shock me.

I don't want to purposefully shock you but it isn't true.

The higher expected return the house wants, the more the player is going to risk losing every time they play. That is just common sense.

Now you're confusing variances in house edge (which in return are variances in expected value) with variances in the variance. The variance simply measures distances away from the expected value rather than measuring the expected value itself.

Take a game of blackjack with a 1% house edge and a game of Jack Or Better Video Poker with a 0.05% house edge. Assuming perfect play, which game has the higher variance? You can answer this through logic rather than using and maths/stats.

[Justin7]

Take a game of blackjack with a 1% house edge and a game of Jack Or Better Video Poker with a 0.05% house edge. Assuming perfect play, which game has the higher variance? You can answer this through logic rather than using and maths/stats.

That is very well articulated for everyone that knows both games.

[reno cool]

Video Poker has more variance because of the rare to hit higher paying hands that make up part of the payback. Try Triple Double Bonus or similar game on Super times-multi strike. You might as well throw expected payback % out the window.
Now a 50-50 game such as BJ would appear to be something of low variance, and maybe it is relatively speaking. However, I think many people are still surprised by how volatile it can be. Of course some of this has to do with the fact you're trying to realize a very small edge.

[donjuan]

There is a relationship between expected return and variance in the finance world. If you want a small expected return with low variance then you go bonds. If you want a higher expected return with medium variance you go large cap stocks. If you want even higher expected return with high variance (risk of negative return) then you go small cap/growth stocks. You can't say, ok I want a high expected return with very low risk. Unless you get inside tips or something you can't acheive this.

This is a fact.

1. This is all assuming an efficient market.
2. This has almost nothing to do with casino games/sports betting.

Now if this isn't true for casino games, it would shock me. The higher expected return the house wants, the more the player is going to risk losing every time they play. That is just common sense.

This simply isn't true. You are confusing risk in finance with nominal amounts at risk in a single bet.

[tacomax]

2. This has almost nothing to do with casino games/sports betting

That is the key flaw.

Taking it further, consider the roulette table with a single zero; the single zero represents the house edge. One player makes 10 bets on red; another player makes 10 bets on number 30. The expected value for each player is identical but the variances are most definitely not. How can different bets on the same game with the same expected value have differing variances if it is the differing of the house edge that dictates the variance?

[WileOut]

Taking it further, consider the roulette table with a single zero; the single zero represents the house edge. One player makes 10 bets on red; another player makes 10 bets on number 30. The expected value for each player is identical but the variances are most definitely not. How can different bets on the same game with the same expected value have differing variances if it is the differing of the house edge that dictates the variance?

But I wasn't comparing 2 different events. I was saying that in any one event (in your example EITHER the bet on red OR the bet on number 30) if you increase the house edge, the variance for the player will increase in a bad way for the player.

I dont know a thing about roulette but if you do something to the table (like if the house cheats by tinkering with the table) that changes the house edge to +5%, then the risk you have in losing a lot of money in betting on the number 30 will rise. Why? Because the expected return is positively correlated to the risk.

In an individual event, if the expected return changes the risk/variance changes as well.

This is my argument, I will leave it at that. Maybe I am way off base here, my knowledge is in finance not casino game statistics.

You guys have a nice night.

[tacomax]

But I wasn't comparing 2 different events. I was saying that in any one event (in your example EITHER the bet on red OR the bet on number 30) if you increase the house edge, the variance for the player will increase in a bad way for the player.

You were saying that the expected value dictates the variance. Your point in the financial markets is totally valid; that is the higher the expected return, the higher the risk and so the higher the variance. However, this does not hold true in the same way for casino games since there is no option to take a higher risk (in terms of differing expected value) on a game assuming you are playing the correct strategy.

Let's consider a roulette game with a 0% house edge. Player 1 makes 10 $1 bets on red - the expected return is $10 since there is no house edge. Player 2 makes 10 $1 bets on the number 32 - the expected return is $10 since there is no house edge. However, the variance for player 2 will be much higher since there is a lower probability of him hitting the number 32 than there is hitting of player 1 hitting red. So: the same game, same house edge but differing variances.

You're taking the financial market and trying to extrapolate your results to a casino game - you can't do that. Well you can, but you'd be wrong.

[markmann]

I've been involved in the development of casino games at an "A" rated book. The game is fair, and the house edge is comperable to a good Las Vegas Strip game.

If you can prove that a good rated book is cheating players - doing what you suggest - it would be news to me. Do you know of a book that does this? I don't think "everyone nos" this.

Hello Justin 7, I have having some serious issues with BETPHOENIX. With a good amount of certainty their casino is set to be more friendly in the early stages of the account... then after some time it gets harder... The real question is, Do the popular casino programs have "adjustments" or variations of the odds for the games??? I beleive the answer is "YES!" Now a good book is notgoing to obviously screw themselves out of a good account... However the lesser books would obviously be looking to pump up a player then dump their ass... Do you have a definative answer for the above question??? Thank you! Mark

[IcE]

I've been involved in the development of casino games at an "A" rated book. The game is fair, and the house edge is comperable to a good Las Vegas Strip game.

If you can prove that a good rated book is cheating players - doing what you suggest - it would be news to me. Do you know of a book that does this? I don't think "everyone nos" this.

Hello Justin 7, I have having some serious issues with BETPHOENIX. With a good amount of certainty their casino is set to be more friendly in the early stages of the account... then after some time it gets harder... The real question is, Do the popular casino programs have "adjustments" or variations of the odds for the games??? I beleive the answer is "YES!" Now a good book is notgoing to obviously screw themselves out of a good account... However the lesser books would obviously be looking to pump up a player then dump their ass... Do you have a definative answer for the above question??? Thank you! Mark

do you relize this is a 4 month old thread?

[Justin7]

I don't know of any casinos that "suck in players" via easy start, and penalize them later. Nothing to my knowledge suggests this is the case with BetPhoenix.

[Ganchrow]

With a good amount of certainty their casino is set to be more friendly in the early stages of the account... then after some time it gets harder...

Based on what evidence are you positing your "good amount of certainty"?

[Sam Odom]

Justin7, (hypothetical) If your mother want to play BJ online with a sportsbook which one would you recommend?

[Justin7]

Justin7, (hypothetical) If your mother want to play BJ online with a sportsbook which one would you recommend?

I'd recommend she dig a hole, and put her money in that hole. When she no longer wants to play online BJ, she'll still have her money.

[aggieshawn]

experimentally the chances are 100%
theoritically 5% per bet

[patswin]

FYI, the software under investigation is ThrillX.

Justin what did you find about this? I've used this at Bet Ed before and the results were not normal and have seen other forum posters warn about Thrillx so I am curious as to what your findings were

[Dark Horse]

The idea that online BJ could have a slightly manipulated house edge has completely undermined my faith in humanity.

If mean, if software can't even be trusted anymore ...

The end is near.

[curinator]

This complaint was actually filed by me prior to being a member on the forums. Justin couldn't prove anything and the casino manager at Beted would not budge an inch on his stance that my results weren't extraordinary and like Justin said, the manager quoted that I had a 6-7% chance of busting after x amount of played hands wagering x amount of dollars without altering my bet size (I forgot the exact numbers now) when in fact, I found the chances to be far less likely (as does math ). I figured nothing would come of the dispute as extraordinary events with extreme odds occur all the time to people in different facets of life and also due to the fact that SBR does not take casino complaints in general, but I still decided to report it as it was highly suspect.

I knew about ThrillX prior to depositing there and knew the risk, but forgo it due to the immense +EV. Beted routinely offers 100% match bonuses at their casino with a rollover that makes it a +EV situation playing blackjack with perfect strategy by their rules. I still get offers from them in my e-mail with 100% match bonuses and only a 20x rollover.These aren't one time sign up bonuses, they are reload bonuses. I think they are willing to offer such a low rollover on blackjack coupled with a 100% match bonus for a reason, that's all I will say.

[patswin]

This complaint was actually filed by me prior to being a member on the forums. Justin couldn't prove anything and the casino manager at Beted would not budge an inch on his stance that my results weren't extraordinary and like Justin said, the manager quoted that I had a 6-7% chance of busting after x amount of played hands wagering x amount of dollars without altering my bet size (I forgot the exact numbers now) when in fact, I found the chances to be far less likely (as does math ). I figured nothing would come of the dispute as extraordinary events with extreme odds occur all the time to people in different facets of life and also due to the fact that SBR does not take casino complaints in general, but I still decided to report it as it was highly suspect.

I knew about ThrillX prior to depositing there and knew the risk, but forgo it due to the immense +EV. Beted routinely offers 100% match bonuses at their casino with a rollover that makes it a +EV situation playing blackjack with perfect strategy by their rules. I still get offers from them in my e-mail with 100% match bonuses and only a 20x rollover.These aren't one time sign up bonuses, they are reload bonuses. I think they are willing to offer such a low rollover on blackjack coupled with a 100% match bonus for a reason, that's all I will say.

I figured it was Bet Ed, yeah I had some really unusual sessions there. I have since had my limits reduced to $25 max wagers so I effectively was shown the door. Since I can't play there anymore I will let you in on a secret - those 100% reload bonuses are good to use in the sports book also. Deposit $500, get $500 cash bonus now you have $1000 in your account. Go to the sportsbook and bet a few games there and bet the opposite side at another shop and try to lose your deposit and bonus at Bet Ed. They will keep sending you the offers, only problem which happened to me was I won all my bets at Bet Ed and had to meet the BJ rollover before I could cash out. Of course I lost all the bonus and then some because the software is rigged but if you can lose your sports book bets this can be a nice little bonus

[blix177]

Someone with some extra cash to burn try this out at bodog, I will bet my 30 points even odds that, that person will lose greater than 250 bets after 3500 games given your using basic strategy.

[hockey216]

6 or 8 deck shoe isnt 0.5% edge. single deck maybe.. 6-8 deck higher house edge

[MadTiger]

Thanks for the link. This suggests it is about 1 in 10,000. This is a far cry from the 6% chance the book quoted. I'll give more facts later, but I need to keep exploring this. This one could get interesting.

I don't know if I posted it here, or on some "other" board, but what I did during my very brief online casino career was I started to "reset" the RNG after every hand (reload the app), to make it more fair. It took way longer, but I wanted a fair situation. Since it was more fair, of course, they caught on, and that doesn't work any longer.

I did it. I won "more." They changed things.

My point in bringing this up is that it was proof to me that, while it wasn't completely "rigged" or anything, online casino gaming still was problematic, and the put in artificial protections for themselves that I didn't see as fair.

(I am not some random paranoid noob, either. Math minor, Comp Sci major, MBA Finance, etc. I know numbers. And they were trying to screw me a bit!)

[MrX]

I don't know if I posted it here, or on some "other" board, but what I did during my very brief online casino career was I started to "reset" the RNG after every hand (reload the app), to make it more fair. It took way longer, but I wanted a fair situation. Since it was more fair, of course, they caught on, and that doesn't work any longer.

I did it. I won "more." They changed things.

My point in bringing this up is that it was proof to me that, while it wasn't completely "rigged" or anything, online casino gaming still was problematic, and the put in artificial protections for themselves that I didn't see as fair.

(I am not some random paranoid noob, either. Math minor, Comp Sci major, MBA Finance, etc. I know numbers. And they were trying to screw me a bit!)

As a computer science major, you must realize that the random numbers were not being generated on your computer. I don't know why restarting the client app would "reset" the RNG. Sure sounds tedious, though.

[purecarnagge]

You guys do math way too much. I hate math. I love betting. How does that work out

[MadTiger]

As a computer science major, you must realize that the random numbers were not being generated on your computer. I don't know why restarting the client app would "reset" the RNG. Sure sounds tedious, though.

Au contraire, mon frere. As you should know, there are multiple methods of SEEDING the RNG. Nice try to catch me, though. Iron sharpens iron.

I reseeded it every time. This is IRRESPECTIVE of where the seed comes from, whether it was a system clock algorithm (my box), or a server-side number (their box).

[JBC77]

They can say whatever they want/believe/were told but unless they allow an independent programmer to look at the source code you cannot be certain about anything.

Bingo......and we all know that won't ever happen. If someone could prove to me it was fair, then I would play.

[MadTiger]

Bingo......and we all know that won't ever happen. If someone could prove to me it was fair, then I would play.

QFT.

I am done with online casino table games. It was a fun month.

[dimon]

that's great thread...my experience, betus on the last deposit i asked for a 100% casino bonus instead of free play...they only game me 30% well I got lucky and after 20x roll over turn these bonus into a 50% of deposit into cash...was told that there is no bonus for me there...just thought I will contribute