Online black jack crazy low % bust hands

Mickyia

Dormant Account
Joined
Oct 8, 2015
Location
Birmingham england
Hi, this is my first post, and have for long time suspected online blackjack is not random,has anyone ever looked at the % bust hands the dealer gets against expectation, and particularly the ammount of bust hands dealer gets when holding a "stiff" first card , I have just recorded 17 sessions of a total of 2600 single hands and the results are unbelievable, any comments would be great

Mike
 
Can you be a little bit more specific please? Tell us the number of hands busted, hands-won%, hands-lost% the name of the game you played and so on.

I've played "Blackjack" (not Blackjack Surrender, Perfect Blackjack, etc.) in August about 20,000 hands and came out over 100% RTP. It's fairly save to say the game is "within expectation".
 
Okay I calculated a little bit:

Sample Size: 2600
Sample Observed Mean: 0.281921
Standard Deviation: 0.45002
Desired Confidence Level (%): 99.9

Results: Confidence Interval: +/- 0.03 (range 0.25 to 0.31)

So the probability of your result (0.212) is far, far below 0.01.


A little bit too early for me to be suspicious though. I had far better results.
 
Hi thanks for that reply , these results were just the last few days , it's very similar on every session, I stopped playing this game for 2 years after losing A LOT of money on Playtech at William hill, these are the only results that seem to prove something not right, in one session of 163 hands the dealer had a 2 or 3 21 times , it only busted once !!
 
Those streaks you are reporting are not at all uncommon. I had them with basically all major game-providers and a small sample size like 21 hands is just not enough to prove anything.

Did you count dealer blackjacks as "non-busted" too ?
 
Hi, these are the results of the past few days playing one hand black jack using 6 decks, my bets were usually £5 or £10
With very occasional increase.

These figures are aimed at the % bust that the dealer has, and in particular the soft cards 2,3,4,5,6

Hands. Dealer bust. Dealer 1st card. Average % bust
Not bust against bust
2. 3. 4. 5. 6.


175. 39. 10/1. 12/4. 8/7. 4/8. 6/6. 22.2%
168. 35. 8/3. 10/2. 6/2. 5/7. 11/8. 20.8%
171. 46. 8/7. 9/7. 3/3. 8/7. 7/10. 26.9%
161. 35. 10/3. 5/5. 7/6. 7/3. 6/2. 21.7%
157. 24. 12/6. 5/1. 8/4. 10/4. 7/2. 15.3%
85. 16. 2/3. 4/3. 2/2. 5/0. 4/0. 18.8%
171. 44. 4/2. 13/4. 8/5. 10/3. 7/3. 25.7%
165. 35. 8/3. 8/2. 5/5. 5/5. 7/5. 21.2%
166. 34. 7/1. 5/3. 3/3. 8/9. 10/7. 20.5%
121. 31. 5/4. 6/2. 2/3. 6/3. 7/5. 25.6%
165. 34. 15/2. 14/3. 1/3. 10/9. 6/3. 20.6%
112. 21. 5/2. 2/5. 3/2. 5/4. 4/1. 18.8%
162. 32. 5/1. 6/4. 7/4. 5/4. 7/3. 19.8%
176. 35. 10/2. 9/2. 5/2. 8/1. 7/5. 19.9%
163. 33. 11/1. 10/0. 7/4. 10/4. 8/6. 20.2%
126. 30. 11/5. 1/1. 5/4. 6/2. 7/4. 23.8%
172. 32. 8/4. 10/4. 4/2. 8/2. 9/5. 18.6%

The actual as per wizard
Of odds is. In %. 35.35. 37.42. 39.58. 41.84. 42.28. 28.19

As you can see out of 17 sessions of 2616 hands not once did the dealer go near the 28.19% needed
My grief has always been with the ammount the dealer does not bust on a stiff card, most of the above % bust
Results on stiff cards are crazily low compared with what it should be.
 
I put your data in a spreadsheet for proper analysis:

MickyiaBJresultsanalysisfinal.JPG

Dealer busts against dealer upcards 2 and 3 have been far below expectation. However the amount of hands played is still to low to conclude the game being non-random. The results for upcards 4, 5 and 6 seem fine to me.
 
Thanks I really appriciate that good work, but don't forget the overall % bust on all cards
This must mean the dealer busts against A,7,8,9,10 and picture cards is way low to expectation ?
 
Your calculation basics are flawed.

You have to be aware that the dealer won't draw a 3rd card, hence won't bust if
- You have a blackjack (X) P=0.047
- You bust (Y)

So according to your numbers:

0.212 = 0.282 x (1-(X+Y))

(X+Y) = 0.248

Y = 0.2012

That means you bust yourself in around every 5th hand and the dealer won't hit a 3rd card making it impossible for him to bust. The dealer won't hit a 3rd card in around every 4th hand.

I also tested it at bet365 right now. The numbers seem consistent.
 
Ah yes , I just became aware of that , so I took out the 14 hands that he couldn't take a 3rd card and the % went from 18.5 to 21.4 on the session I chose, so yes take your point and I will do the others but still will be way below 28.2 % I think
 
I recommend you run another test.
Count the amount of busts for each dealer upcard and remove the hands where you have a BJ or bust (also those where the dealer does not stand on 16 or lower). You will have a significantly lower amount of 7-A hands compared to 2-6 because you need to hit more aggressively on those and bust more often so that you need to remove them from your analysis. However your results will be consistent with the 28.2% bust assumption when you weight them 1/13 for each dealer upcard in the end.
 
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