 Ask the Wizard: |
Fairness of online casinos, and disputes |
Hi Wizard, I came across a new online casino, and decided to give it a try. I was playing at
their craps table and noticed that on 20 rolls of the dice, the field bet lost 16 times, and won only 4 times. The sequence went like this: L6,W1,L1,W1,L1,W1,L2,W1,L6. I realize this is a small sample, but is it enough to pass some sort of assessment as to whether this new casino is legit or not?
— Mark from Ottawa, Ontario
The probability of an event with probability p happening x times, out of a possible n, is combin(n,x) × p x × (1-p) (n-x). In this case, p=4/9, x=4, and n=20. Here is the probability for all possible number of number of field rolls out of 20:
| Bad Beat Combinations |
| Wins |
Probability |
| 0 | 0.000008 |
| 1 | 0.000126 |
| 2 | 0.000954 |
| 3 | 0.004579 |
| 4 | 0.015567 |
| 5 | 0.039851 |
| 6 | 0.079703 |
| 7 | 0.127524 |
| 8 | 0.165782 |
| 9 | 0.176834 |
| 10 | 0.155614 |
| 11 | 0.113174 |
| 12 | 0.067904 |
| 13 | 0.033430 |
| 14 | 0.013372 |
| 15 | 0.004279 |
| 16 | 0.001070 |
| 17 | 0.000201 |
| 18 | 0.000027 |
| 19 | 0.000002 |
| 20 | 0.000000 |
| Total | 1.000000 |
Taking the sum for 0 to 4, the probability is 2.12%. So, this could have easily happened in a fair game. September 29, 2008
How can I prove an Internet casino is cheating at blackjack? - Ed from Indianapolis
As I've said before you need to gather some evidence. If you're not sure how they are cheating then a simple tally of total initial bets made and units lost will suffice. You should flat bet one hand at a time, play perfect basic strategy, and do not count money bet doubling and splitting towards number of bets made. If based on your results the probability of your losses are less than 1 in 10,000 I think there is reason to be suspicious, and would be interested in seeing your evidence so that I may try to corroborate it. Based on a house edge of 0.5% and a standard deviation of 1.15 here is how much you need to be down according to the number of hands. This is based on total hands played since you started keeping track.
| 0.01% Losing Percentile in Blackjack |
| Hands |
Net Loss |
| 100 | 43 |
| 200 | 61 |
| 500 | 98 |
| 1000 | 140 |
| 2000 | 201 |
| 5000 | 327 |
| 10000 | 478 |
The formula for being down x units of y hands played is shown in my FAQ.
Jan. 3, 2006
I have been playing for "fun" at online casinos and am considering playing for real. However, some casinos state that when playing for fun the Windows RNG is used and when playing for real the UNIX RNG is used. Will the difference in RNG's affect my win probability? Thank you! - Vicki from Mechanicsburg
That shouldn't change the odds at all. The Windows RNG is probably not very good, but good enough for free play. However when real money is on the line a smart operation would use a proven good RNG on their own end.
Nov. 22, 2005I have been researching Casino Bar because they have a nice bonus today. I ran across your claim that their software does the equivalent of "dealing seconds", but I see that your information was last updated about two years ago. I was wondering if you know of any change in that situation, please. I suspect you would have updated the page if there had been a change, but I thought I would ask. Where could I find a basic strategy sheet for a casino dealing seconds? (the bonus may or may not still be playable). Am I right in thinking the house edge is close to 5% in such a game? Of course, if that is the case I may as well play tricard poker. Thank you for a great website. Do you accept donations? Regards, - Ricardo from Malden, MA
When I find a casino is not playing fair I don't generally go back to check if they've stopped. Sometimes I do if requested by the casino and I feel the problem may have been accidental. Following is a basic strategy, based on infinite decks, where the dealer stands on soft 17 and deals seconds. What I mean by dealing seconds is that if the third card, and only the third card, would break the dealer it is skipped and the next card is played, whatever it is. Otherwise play continues normally. The house edge under this game would be 9.3%. I used to ask for donations but got so few I quit asking. Now the site is comfortably supported by advertising revenue anyway. However I would be happy if you sent a donation to either the Appalachian Trail Conservancy or Strive.
Nov. 9, 2005
Thank your for your informative column. I have been using the "Fun" mode to practice the basic blackjack strategy online (Golden Palace and Grand Online Casino). I generally do well on the fun mode, but when I go to "Real Money" mode I start losing quickly using the same strategy. Do the online casinos change the software randomness for "Fun" mode letting us win, only to entice us to deposit real money. - Mike from Prescott AZ
You're welcome. It's rare for online casinos to intentionally let players win in free mode. I know the Elka casinos used to do this (for which I blacklisted them), but fortunately they seem to have vanished. If anyone can show me hard evidence that a casino is intentionally allowing players to win in fun mode I would be happy to investigate it. Hard evidence means, at a bare minimum, a record of hands won and lost in each mode, for several dozen hands. Simply telling me that you lost "a lot more" when in real mode is useless.
Nov. 9, 2005
Very simple question on the online gaming side. Casino
states that their RNG gives back for example 96.7. We're all
aware that payment companies charge them as a merchant,
let's say an industry avg. 3.5% transaction fee on the drop
(not on the take). So where is the operator making all their
money or are the RNG's all playing with us? -- Josh from
Stamford
The 96.7% applies to total money bet and
transaction fees generally only apply to deposits and/or
withdrawals. Players generally circulate through the same
money and thus bet much more than they deposit. As I
discussed in the September 18, 2005, column a player
could bet through about 1.5 million dollars with a
$10,000 bankroll and betting $5 at a time in blackjack.
In this case the casino would make their profit based on
1.5 million in bets but pay expenses based only on
$10,000.
Oct. 3, 2005
A colleague of mine was recently playing at [an
online] casino playing 10-line Jacks or Better Video
Poker. Money was deposited and 10 hands were played. All 10
hands (and thus all 100 lines) failed to bring up a single
win. Please can you calculate the probability of drawing a
blank on 10 hands of 10 line JoB. Also, would the probabilty
you calculate be evidence of a rigged game? Thanks in
advance and keep up the (very) good work.
Here is the probability of winning zero per game
according to the number of plays.
|
Probability of Winning Zero in n-play Video
Poker
|
|
Plays
|
Probability
|
|
3
|
0.26260274
|
|
5
|
0.1301204
|
|
10
|
0.02591377
|
|
15
|
0.00649444
|
|
25
|
0.0007854
|
|
50
|
0.00002178
|
|
75
|
0.00000076
|
|
100
|
0
|
The table is based on a random simulation. I know it
is theoretically possible to get a win of zero in
100-play, but in 15,820,000 games it just never happened.
So please don't write about that. The table shows the
probability of getting zero in 10-play is 0.025914, or
2.59%. The probability of this happening ten times in a
row is 0.02591410 = 1 in
7,323,073,295,177,980.
I tried the software in question in free-play mode and
my results seemed fine. In particular in 10 games I won
something every time. However as far as I know no casino
offers this software and takes real money players from
the U.S. I'll plan to do some further investigating but
don't want to explain how in this forum.
April 3, 2005
I would like to know how to test an online roulette
game, to know the odds and if the odds are honest?
First let me say how not to test any game. You
should not record all your play and when you are done
look for any kind of anomaly, and then write to me
complaining that the casino is cheating. The correct way
is to state a hypothesis for how the casino is cheating
FIRST, then gather data, and finally see if the data fits
your hypothesis. If you don't know what kind of
hypothesis to state I would suggest simply testing for
the number of wins and losses, and then bet the same
thing every time. If you do the first two steps properly
and need help on the third then feel free to write me.
Jan. 23, 2005
If a casino doesn't pay you your winnings, and you
meet all requirements, and then they turn around and say
that you've done something, but will not give you proof,
what is that considered as? Fraud? Illegal? What? I'd really
like to know.
Nothing is illegal in the unregulated world of
Internet gambling, except maybe out of the British
Channel Islands. Based on only your side of this I'd
call it fraud. One of the purposes of my site is to
advertise only reputable casinos so that you can find a
safe place to play online without running into this kind
of problem. If you click an advertiser's banner on my
site, open an account with them, have problems, and are
unable to resolve them with the casino, then I'll
help arbitrate. But I'm almost never called on to
help because I pick only reputable casinos in the first
place and players by and large don't have problems there.
I know this doesn't help for your current situation but
it may help for next time, and it can certainly help
anyone reading this who needs help picking an online
casino in the future. Since online gaming is mostly
unregulated it's extra important to pick a reputable
casino in the first place. Good luck with your dispute.
Jan. 2, 2005
What should I do if an online casino refuses to pay
out winnings?
If the casino is one of our advertisers and you
signed up after clicking an ad on our site then I
will help as an arbitrator. However it is unlikely
you would have trouble getting paid by one of our
advertisers since we allow advertising from only the most
reputable casinos in the business. The number of times I
have had to intervene because a player did not get paid
by one of our advertisers is extremely small.
If the casino is not one of our advertisers then I
can't really do anything for you. In that case you should
give the casino at least a month and three warnings to
pay. It goes without saying that you should make sure you
have complied with all the casino's requirements for a
withdrawal, especially any ID requirements. If you have
been communicating only by email and haven't heard from
them then make sure to call them too. It may be the case
that your spam blocker is preventing you from getting
their email explaining what they need from you in order
to process your withdrawal. If all else fails go on the
bulletin boards such as Casino
Meister and warn others about your experience. Be
sure to include plenty of detail -- posts that say only,
"Casino X won't pay me, don't play there!" are not very
helpful.
VegasClick has an
article about disputes with online casinos.
Dec. 20, 2004
When I play in free-play mode at an online casino does
it have any effect when I play for real money? I think
definitely not, but I wanted to check with you.
It shouldn't. And I
will vouch that any casino advertising on this site
plays a fair game. Any casino I find cheating, whether in
fun or real money, I will have no compunction to add to
my blacklist. Oct. 17,
2004
I bet on the Internet on soccer games. The games are
supposed to start at 10am but I was able to make my bets at
10:25. All my bets were accepted at 10:25. So if the bets
are accepted there is nothing we can do about it. The
Internet casino doesn't have a right to cancel those wagers,
they are supposed to pay my winnings.
First, the vast majority of Internet gambling is
unregulated. So there is likely no higher authority you
can turn to. The word of the casino/sport-book is final.
I would imagine that somewhere in their lengthy terms and
conditions is a rule that says that wagers made after the
beginning of an event are not official, even if accepted
by the system. Even without that most have a general rule
that if a line is obviously in error then even if the
system accepts it can be voided. Such I think could be
the situation here. Oct. 8,
2004
Do you think online poker room is "fair" in general?
Yes? Maybe? Or don't ever touch it. I figured it is almost
impossible to find out if the casino or other players are
cheating you.
I doubt the casino would cheat, why would they?
The bigger concern is the other players. It would be very
easy for players to collude over the phone or instant
messenger. Whether they actually do or not I don't know.
There is probably a greater risk for that at the higher
limit tables. Aug. 23,
2004
Hi, I found a Double Exposure game where the ties
push. The full rules are:
- 6 decks.
- Dealer hits soft 17.
- All ties push, except player wins tied
blackjack.
- Player can double on hard 9 to 11 only.
- Player can resplit, including unlike tens, to 4
hands.
- Double after split allowed.
- Draw to split aces allowed.
This must have a player advantage, can you tell me
what it is?
As I'm sure you know this game is offered by
Lucky Chance
casino. Using the appropriate basic strategy for
these rules the player advantage is 7.2%! Wait it gets
even better. You can bet three hands at once of $5 or
more each and if you get a blackjack on all three you win
a progressive jackpot that is currently at $18095. The
probability of getting three blackjacks in three hands is
1 in 10552. So the progressive is worth an extra $1.71
per hand. On two days while I played they also offered
15% rebate on losses, calculated whenever you exited the
game. So I simply exited after every hand, except on a
push.
However I'm always suspicious when the player
advantage is too high. I checked Winner
Online and found they allegedly used to offer a video
poker game with a 120% return, although they use a normal
pay table now. That is two red flags. Lucky Chance offers
a 100% immediately bonus up to purchases of $500, so I
put them to the test. It was my goal to either make a
fortune on their Double Exposure game or prove the game
was not fair. Following are my results:
- 313 of single hands: net win of 32 units.
- 1959 hands of 3 spots at once: net loss of 29
units.
- 2272 total hands: net win of 3 units.
Given a 7.2% advantage my expected win was 163.6
units. The probability of only winning 3 or less is
12.4%. This is using a standard deviation of 1.17 for a
single hand and 2.68 per hand for playing three at time.
My source of the 1.17 is a random simulation using
Stanford Wong's Blackjack Count Analyzer and I
multiplied that by 2.28 for 3 hands, based on the
standard deviations for regular blackjack for 1 and 3
hands as found in my blackjack
appendix 4.
This certainly does not rise anywhere near enough to
make any accusations. In addition I recorded results all
sorts of ways but every test came out looking normal. I
would have played longer but the game play is extremely
slow and I went broke. The reason I went broke is I did
worse on larger bet sizes and my first few hours I didn't
record results but they were not good.
So I failed on both my goals. I was too skeptical to
deposit again and already wasted several hours on the
game. However if you wish to take a crack at it then be
my guest. Aug. 12,
2004
Brilliant Site. My question is whether or not free
online demo games follow the same system as their money
playing counterparts. I ask because I was playing
Netgaming.com's
free roulette and it appeared as though the system was
purposely letting you win in order to bait you into playing
for money. Do online sites do this? I was basically trying
the Martingale, which I know is false, but I turned the 1000
very quickly and easily into 10000.
To answer your question I gave Netgaming a try.
In their single zero roulette game I placed 200 bets on
red. My results were 133 wins and 67 losses. The
probability of 133 or more wins in 200 spins is 1 in
3,788,515. So obviously they were letting me win. Let the
record show I do not approve of manipulating the odds for
any reason. So to Netgaming.com,
and any other casinos that do this, I say shame on you.
Netgaming is now on my blacklist.
May 13, 2004
Do Internet casinos deliberately let you win in fun
mode?
I have heard this allegation a lot of times but
have yet to see any proof either way.
April 22, 2004
How does an online poker sites protect its customers
from collaboration?
I'm not sure, but they swear that they have
tests for this. They wouldn't want to explain exactly
what they test for, lest the collaborators take
countermeasures. However an easy sign would be when 2 or
more players always play at the same time.
Feb. 27, 2004
I have down loaded many black jack games from internet
both stand alone and on-line. Had played for long time and
felt the games are different in difficulty to win especially
the slot, (pardon me if I am wrong). If it is true than is
there any way to find out if the online games are truly
random or any trusted organization we can get truly depend
on? - Clint from Singapore
It is a good sign if a casino has an independent
auditor to review the log files for fairness and
randomness. This is a service I personally provide. In
the last year I have done so for all the Odds
On casinos and Infinite
Casino. You can read more about my business services
at www.gamingmath.com.
My apologies for the blatant plug.
Nov. 28, 2002
Would it be possible to use a Java decompiler to look
at the source code of the Unified Gaming blackjack applet
(and determine whether the game is fair or not)? - Mark from
Allston, Massachusetts
This is not my area of expertise but I speculate
that if they are cheating a decompiler would not prove
it. Ultimately the random numbers and cards are drawn on
their end, which if there were any cheating going on is
where it would happen. March 11,
2001
I recently won a VERY LARGE jackpot on an on-line
casino, and immediately cashed out. The casino is now
claiming that it will take them about three weeks to "audit"
my account before they will process the payment. Once they
begin processing the payment, it will take 5 to 10 business
days before they send the funds to me. They will not pay
more than $4,000 per week. Further they are charging me $15
per $1,000 to perform a wire transfer to my bank account.
Or, if I elect, they will charge $10 per $1,000 to mail me a
check, which they claim takes 2 to 6 weeks to process. If I
wish I can pay an additional $35 per check (remember checks
are no greater than $4,000) to have the check FedEx'd to me.
They never had much difficulty taking money from my credit
card accounts. I am wondering if this is standard fare for
on-line casinos... and if there is anyway around these
delays and exorbitant charges? ñ Mike from California
I figured this was a Microgaming casino based on
the fees for a payment. This is news to me so I called
three Microgaming casinos to ask about it. The River
Belle said they pay any jackpot in its entirety up front.
The Golden Palace did as you describe, paying $4000 per
week. The English Harbour pays $5000 per week. You have a
legitimate complaint about paying the service fee on
every payment, as well as the show payment processing
time. Unfortunately there is nothing you can do to change
it. As I have said before there is almost no regulation
of most online casinos so they can do whatever they
want. Oct. 5, 2000
What other options are open to an online casino player
if they are dissatisfied with an online casinos response to
a problem? My particular gripes are removal of a bonus for
inactivity and requiring a copy of a credit card statement
to cash out winnings. -- Rod from Newburgh, U.S.
A: There is not much you can do in the way of
complaining to a higher authority. Some of the better
jurisdictions have a government body to oversee the
online casinos. However if you ever bring a specific
complaint to their attention they seem to either do
nothing or side with the casino. It is much more
effective to raise a stink on Internet bulletin boards.
This will usually not help resolve the problem but may
give you some satisfaction of getting back at the casino.
Gambling.com
offers a service in which a disgruntled player can bring
up a complaint and they will let the online casino
respond to the charges. Sometimes this exposure motives
the casino to correct a problem or offer a compromise.
Most casinos will respond. In many cases the dispute is
the result of the player trying to defraud the casino or
a misunderstanding of the rules on the player's
part. Sept. 3, 2000
Q: I have just started gambling online and I am having
a difficult time believing that these online casinos are
really fair. although I have tried just three different
casinos, they seem to be very hard to beat. I am a fairly
consistent winner in Vegas at Blackjack, but these online
guys are tough. So the question is-- are the online
Blackjack games really fair. Thanks and by the way, I really
enjoy your site. I have learned a great deal and am looking
forward to applying some of your knowlege during my next
trip to Vegas. thank again!! - Larry R. from Nucla, USA
A: Thanks for your kind words. I think that the
vast majority on online casinos are fair. However I won't
claim that all of them are. Check out my casino
blacklist for casinos I had problems with. Assuming
you aren't playing one of the few bad ones I would
suggest your losing is just the result of bad
luck. Aug. 20, 2000
Q: Thank you for you website, it answered a lot of
questions. For online casinos that are downloaded, are the
games played from the server or on your personal computer.
The reason I ask is that you suspect some casinos of
cheating. So does the downloadable games protect you from
cheating because the game is played off your computer.
Specifically, in roulette for example, the number that pops
up, is it determined by the online server or the downloaded
program on your computer? And if there are cheats, do you
suspect that the programs were written to cheat or are there
live people regulating your play? - Tom Wang of Los Angeles,
California.
A: No, when you download software you are still
playing a game based on a server elsewhere. The day may
come when people can play on their own computers but
casinos would have to worry about you cheating. Whether
downloadable or Java the number that pops up in roulette
is determined by a remote server. The software on your
end just presents the graphics and establishes
communication with the online casino's server. I do
suspect that some casinos cheat based on repeated reports
of incredible losses from other players. If they do it,
how they do it I'm not sure.
July 2, 2000
Q: Great site. Do programs like Microgaming "learn" to
defeat the player? I was under the assumption that the
answer is no until I played "Don't Pass" in craps. Out of 39
"hands" 28 were Pass, 10 were Don't Pass and 1 was a 12 on
the come out roll. I realize that this can happen, but it
made me wonder. I had read elsewhere that the software can
"learn". I didn't really believe it. No, I didn't lose a
lot, my betting unit is $1. I'm "testing" onliine for
myself. - Rosalyn Blanchette from South San Francisco,
California
A: No, programs like Microgaming do not learn to
defeat the players. Reputable companies like Microgaming
do not need to play any dirty tricks to make money but
realize that there is more money to be made long-term by
offering a fair game. Even if they did want to cheat the
players there would be much easier ways to do so.
However there is a lot to be said about computer
teaching themselves to play. I'm not an expert but I do
know that computers can learn from past experience in
games like backgammon and chess to improve their play.
Finding
the Edge (Edited by Olaf Vancura, Judy A. Collins,
and William R. Eadington) has a paper titled 'A Computer
Teaches Itself to Play Blackjack' by Olaf Vancura if you
are interested in learning more about the
topic. June 25,
2000
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