Is PartyPoker rigged?

[dacium]

Firstly let me just say I have never believed the crap about online games being rigged. I have suffered the huge down swings and up swings, however I have never experienced anything as bad as this.

My friend and I just had an insane loosing streak on party poker multi blackjack. we lost about $1000 in 3500 hands playing basic strategy flat betting $1. It started out as loosing $100 in about 300 hands, and we continued on and on and our rate of loosing never improved. The dealer seemed to have a huge run of getting 10 cards up and never getting 6's. This also resulted it huge amounts of blackjacks.

In total we played 3513 hands (which party poker makes you view one per page per hand and only stores upto 500 and only for 3 days).

I had to write a c program and combined with perl scripts I am extracting all the hand history. Here is the dealer up cards:

2  234
3  177
4  128
5  323
6  178
7  261
8  323
9  321
T  355
J  291
Q 332
K 305
A 285

Out of 3513 hands the expected value was 249.4.
The standard deviation is 15.79

Obviously there are huge problems here.
4's occured just 128 times, thats 7.68 standard deviations from expected!

The average up card is 4 standard deviations away from expected value! The chance that this combination was drawn randomly is therefore about 4 deviations (99.99366575163%), which is 1 in 15,787!

Party-poker is probably the place I would never expect to be rigged but it has totally lost my confidence.

I am using a perl script to sort the results and I am trying to get the results of double downs won/lost and the ratio of blackjacks for player to dealer also.

[moo321]

I've had 3 SD losses at places that I don't consider to be rigged. I've also had 3 SD wins at places I don't consider to be rigged. I'd say it's pretty doubtful that it's rigged. Too many people playing on there.

[aka23]

Losing $1000 over 3500 $1 hands is about 15 standard deviations below the mean. You said you played "multi-blackjack." Were you playing single-hand or multi-hand? Many people have played Party Blackjack and have had results near normal expectations. I've never heard of anything like a 15 standard deviation loss before. However, the play does sometimes feel unnatural, more so than other softwares.

Party is a publicly traded company, so it seems unlikely that they would put so much at risk by making an obviously rigged game. If you still have the full hand history, I'd recommend contacting both Party and Wizard of Odds with your results. Party may give an explanation for the results, if contacted. And Wizard of Odds has a good amount of experience analyzing such results. His findings are highly respected by the gambling community.

[shadroch]

Was this your first time playing? If not,have you had any insane winning streaks?

[aka23]

Originally Posted by dacium

Out of 3513 hands the expected value was 249.4.
The standard deviation is 15.79

Isn't variance 249.4, rather than expected value? Unless I'm missing something:

Mean (expected value) = 3513/13 = 270.2
Variance = 3513*(1/13)*(12/13) = 249.4
Standard Deviation = SQRT(variance) = 15.79

[ScottH]

Were you playing correct BS?

[KenSmith]

I used a Chi-Square calculator here:
http://www.physics.csbsju.edu/stats/chi-square.html

I plugged in the expected value for each dealer upcard (270, since this calculator doesn't allow decimal places), and the actual values from the initial post in this thread.

The results:
---------------------
13 data/expectation pairs (x,E):
( 234. , 270.0 ); ( 177. , 270.0 ); ( 128. , 270.0 ); ( 323. , 270.0 ); ( 178. , 270.0 ); ( 261. , 270.0 ); ( 323. , 270.0 ); ( 321. , 270.0 ); ( 355. , 270.0 ); ( 291. , 270.0 ); ( 332. , 270.0 ); ( 395. , 270.0 ); ( 285. , 270.0 );
chi-square = 275.
degrees of freedom = 12
probability = 0.000

---------------------

So, to 3 decimal places, the chance of getting a result that skewed is 0.000.

This is not the first time I've heard flaky numbers from PartyPoker. I would steer clear of this game.

[KenSmith]

Since the online calculator returned a value of zero, I decided to run this test in Excel instead. The result?
1.2094E-40, or
0.00000000000000000000000000000000000000012094
This is quite likely beyond any meaningful precision limits of Excel, so just call it ZERO.

A second independent set of data would be quite useful to see.

[ScottH]

I don't know whether or not PP blackjack is rigged, but back in the day when I was a gambler I had both really good, and really bad results. It wasn't just on the negative side...

However, my massive positive run was right at the beginning, and it was only downhill from there. They could rig it to do good for you to suck you in, and then "flip the switch" or something, I don't know.

[Brutus]

This is not the first time I've heard flaky numbers from PartyPoker. I would steer clear of this game.

wasnt there a thread about this a year ago?