What is the likelihood of this?

[winnington]

Gave the 100% match bonus at bet365 a shot. Played all hands by the book... the result was 5 hands won, 4 push, and 21 losses. Played one $15 hand, all the rest were $5-$10 hands until I was under $10.

Is this within normal variance? Just curious, as I've seen other people here question whether bet365 is fair.

edit: how do I make these images show up? I took screenshots of my bet and hand history.

 

[Pulver]

Unlucky, yes, uncommon, no. My worst result in blackjack is 20 hands lost in a row. So these things happen from time to time, thats why it is called gambling. Next time maybe you win 20 and loose 5..

 

[big_mac]

The short answer is that is far too small a sample to be sure of anything.

I tried an online probability calculator, and that said about 0.1% (1 in 1,000) which seems plausible.

 

[NASHVEGAS]

BJ I assume, Can answer but 30 hands will mean nothing and the question can be calculated several different ways based on how worded iirc.

Not trying to be a smart ass, would help if you could gather more data but I understand if you may not want to.

BJ Basic Expectation
Win=~48%
Loss=~43%
Tie=~9%

Sorry not answering what I believe you want to know but maybe AKA, or some others will then I assume repeat you need more data. 33 units lost in 100 hands has approx. 1/400 prob. Will calculate though as strictly from memory!!

 

[DaveG39]

BJ I assume, Can answer but 30 hands will mean nothing and the question can be calculated several different ways based on how worded iirc.

Not trying to be a smart ass, would help if you could gather more data but I understand if you may not want to.

BJ Basic Expectation
Win=~48%
Loss=~43%
Tie=~9%

Sorry not answering what I believe you want to know but maybe AKA, or some others will then I assume repeat you need more data. IIRC, 33 units lost in 100 hands has approx. 1/400 prob. Will calculate though as strictly from memory!!

Given these probabilities (ty Nash) for wins and losses (ties push and aren't calculated), and using the formula from Wizard of Odds used to calculate such things, I get approximately 1/30,000 of this happening, but 26 hands is a very small sample.

P.S. IIRC..please translate

 

[winnington]

Yeah, it's a rather small sample. Tried to post more info, except my screenshots were blocked for some reason. The only reason I bothered posting is that I've seen a few other people question the variance at this particular casino. Don't want to seem like a sore loser, I'm just curious.

btw, Pulver, the chances of losing 20 hands straight in bj is pretty close to 1 in 10 million (that's an easy calc). Unless you've played millions of hands of bj, I'd definitely be questioning the fairness of whatever casino that happened at... assuming it's online.

 

[winnington]

Given these probabilities (ty Nash) for wins and losses (ties push and aren't calculated), and using the formula from Wizard of Odds used to calculate such things, I get approximately 1/30,000 of this happening, but 31 hands is a very small sample.

P.S. IIRC..please translate

Thanks Dave. Small sample aside, given other users feedback with similar experiences there, I won't be depositing there again.

 

[NASHVEGAS]

Given these probabilities (ty Nash) for wins and losses (ties push and aren't calculated), and using the formula from Wizard of Odds used to calculate such things, I get approximately 1/30,000 of this happening, but 31 hands is a very small sample.

P.S. IIRC..please translate

Should have removed after I calculated and of course rule assumptions were made. Could have been Bakky and not BJ.......30 hands IIRC, LOL!!

 

[winnington]

Oh yeah, forgot to mention it was BJ.

 

[Pulver]

Sorry for getting my facts wrong in my previous post. I checked through some old posts I have at a different gambling forum and found out that I lost 12 hands, had 1 push and then lost another 6.

Anyways, if you play enough spins on the roulette, or hands at the blackjack table, strange things will hapen that makes you ponder. But I have also been very lucky sometimes. These things can go both ways.

 

[NASHVEGAS]

Given these probabilities (ty Nash) for wins and losses (ties push and aren't calculated), and using the formula from Wizard of Odds used to calculate such things, I get approximately 1/30,000 of this happening, but 26 hands is a very small sample.

P.S. IIRC..please translate

Dave, I did not calculate the above but if pushes thrown out then ~52%/~48% as am sure you know. Gotta love that 48%, can't make up it's mind

 

[DaveG39]

Thanks Dave. Small sample aside, given other users feedback with similar experiences there, I won't be depositing there again.

yw, btw,to clarify, that 1/30,000 number is the chance of winning exactly 5 hands out of 26. The more important number is probably the probility of winning 5 hands or less, which is about 1/24,000.

 

[DaveG39]

Dave, I did not calculate the above but if pushes thrown out then ~52%/~48% as am sure you know. Gotta love that 48%, can't make up it's mind

OK, I found the actuals on WoO

Win =~ 42.5%
Tie =~8.5%
Loss=~ 49%

Although I'm sure this will vary depending on the house rules.

Winnington's original example of 5 wins (or less) out of 26 non-ties then becomes a 1/2650 shot.

 

[winnington]

My knowledge of statistics isn't great, but from what I know that's the chances of this happening regardless of sample size. The odds are adjusted accordingly to the size of the sample (i.e. if the sample size were doubled and I had double the wins, the odds would not be the same, they would be much worse).

This was my run from start to finish, it's not like a grabbed the worst section of a longer run.

Seems fishy to me, but not impossible of course.

 

[winnington]

images:

 

[winnington]

After reviewing the images a second time, I guess I had 6 wins.

 

[Jasminebed]

Not a blackjack pro, and I'm not sure of the particulars of the BJ variant (how many decks, etc), but you made at least one mistake in failing to hit A2 against dealer Q, and played other than basic strategy in not hitting soft 18 against dealer 10 spot on another hand.

 

[jas2587]

Given these probabilities (ty Nash) for wins and losses (ties push and aren't calculated), and using the formula from Wizard of Odds used to calculate such things, I get approximately 1/30,000 of this happening, but 26 hands is a very small sample.

P.S. IIRC..please translate

pssstttt if I am correct it is

If I recollect Correctly
could be remember also

Nash has a way with words

Cindy

 

[TOC]

It appears that you kept hitting on 16 three times, that's a no no! You had a 7 & 9 house cards which is 16 and you kept pressing your luck. 16 is a great bust card for the house, normally. It might have not turned out to be a good run but at a quick glance some basic 21 norms were overlooked. My 2 cents..

 

[shiftyy]

online casino

You like the online casino, you like the poker? here you are place : *snip*

 

[zebedy]

You like the online casino, you like the poker? here you are place : gemisirius.gemisland.

is it spam and eggs or spam on toast for dinner today

 

[funeral979]

I had a run about 5 months ago of 28 hands that ended up being 1 win, 1 push, and 26 losses.

I had a run 5 weeks ago that was 21 hands that ended up being 3 wins, 1 push, and 17 losses.

I just had a run 2 hours ago (RIGHT when I switched to max bet...thankfully table max was only $25 and I was playing with a large bonus) of 12 hands that was 0 wins, 2 pushes, and 10 losses (funny, I redeemed my $2 of comp points and went back to BJ and won that hand).

All of these were RTG, btw.

Now obviously these are simply small samples and don't mean much as you need thousands of hands to prove anything yadda yadda yadda...

But you know I get lots of streaks like this all the time...and others do to. Can you remember the last time you played BJ online and won 15 of 20 hands or something similar? Neither can I.

I do not trust blackjack on ANY software platform, especially at higher limits.
If you don't want to flat bet at a buck or two a pop, you are a goner.

 

[winnington]

you made at least one mistake in failing to hit A2 against dealer Q, and played other than basic strategy in not hitting soft 18 against dealer 10 spot on another hand.

Wow, I don't even remember that, nice catch. Obviously staying on a soft 13 wasn't intentional... perhaps my problem is using a laptop with a sensitive touchpad.

Also good catch on the soft 18. I usually use a strategy card, but I never referenced it in this case because I thought the rule was to never hit on 18 or above. I double checked the strategy card for playtech's brand of blackjack and you are correct

Very helpful... I guess my BJ knowledge isn't as great as I thought it was.

 

[winnington]

It appears that you kept hitting on 16 three times, that's a no no! You had a 7 & 9 house cards which is 16 and you kept pressing your luck. 16 is a great bust card for the house, normally. It might have not turned out to be a good run but at a quick glance some basic 21 norms were overlooked. My 2 cents..

Actually, you're always supposed to hit on 16 unless the dealer is showing a "bust card", there's no debating it. Keep in mind the dealer's up card is on the far left.

 

[TOC]

Unless I'm seeing something wrong you hit against the dealer 16 3 times, no way thats correct, sorry. Look 2 times the dealer would have busted, you had the exact same hand.

 

[winnington]

Unless I'm seeing something wrong you hit against the dealer 16 3 times, no way thats correct, sorry.

It is absolutely correct. I hit on a hard 16 versus the dealer showing an A, and twice against a 10. You only stay on a hard 16 when the dealer is showing 2-6.

Here's the strategy card for this particular casino:Link Removed ( Old/Invalid)

You will not find a strategy card anywhere that advises to stay on a hard 16 versus an Ace or 10, although it is a popular mistake that people make.

If you're a BJ player, I highly recommend you use a strategy card while playing until you get it memorized. These are calculated using the statistical odds of winning (preferably suited to the rules of the casino you're playing). I know you might not want to take advice from someone who just went on a terrible run, but I'm sure I'd be backed up on this.

 

[TOC]

Please I don't need a BJ lesson. Look your pics show you hitting 16 3 times, 7 9 card when you should have stayed at some point. I'm not saying you would have beat the house by doing this, just bad card playing. No hard feelings just pointing this out because you made the thread look like the casino was beating you up! I know the game, don't need links but thanks anyway.. The facts are your screen shots my friend. Why is everyone so defensive on this board? Relax..

 

[winnington]

Please I don't need a BJ lesson. Look your pics show you hitting 16 3 times, 7 9 card when you should have stayed at some point. I'm not saying you would have beat the house by doing this, just bad card playing. No hard feelings just pointing this out because you made the thread look like the casino was beating you up! I know the game, don't need links but thanks anyway.. The facts are your screen shots my friend. Why is everyone so defensive on this board? Relax..

Hey, when someone pointed out that I should have hit on a soft 18 vs. a 10, I didn't get defensive, I can man up and admit when I'm wrong...

Because when you're wrong, you're wrong... and staying on a 16 versus a 10 or A is the wrong thing to do. Doesn't matter if you hit 3 times on 16 and bust each time - hitting in that situation is statistically the right thing to do every time.

 

[NASHVEGAS]

Did I see soft 18 not doubled against a dealer's 3 upcard, just glanced at all though including posts

Maybe Eliot will come set the record straight on 16 or I could for most games,decks,rules.

OK!! General B.S. (Most Vegas Games)
If possible, surrender 7,9 and 6,10 against dealer's 9,10,A otherwise hit
Always split 8's (unless dealer hits soft 17, then surrender 8,8 against dealer's A--usually in 6 to 8 deck game)
7,9 and 6,10 against dealer's 2 thru 6, stay
7,9 and 6,10 against dealer's 7 or 8, hit
Soft 16 always hit but double against dealer's 4,5, or 6

A three or more card 16 against dealer's 10 that includes a 4 or 5 you can stay where you normally hit but the difference in expectation is very minimal.


LOL Cindy, Laughing Out Loud

 

[zap987]

Please I don't need a BJ lesson. Look your pics show you hitting 16 3 times, 7 9 card when you should have stayed at some point. I'm not saying you would have beat the house by doing this, just bad card playing. No hard feelings just pointing this out because you made the thread look like the casino was beating you up! I know the game, don't need links but thanks anyway.. The facts are your screen shots my friend. Why is everyone so defensive on this board? Relax..

It seems you do. Of course blackjack would be very easy if you could see both the dealers cards before deciding what to do, but for the rest of us hitting 15 vs dealer 9 is correct.

 

[jas2587]

Did I see soft 18 not doubled against a dealer's 3 upcard, just glanced at all though including posts

Maybe Eliot will come set the record straight on 16 or I could for most games,decks,rules.

OK!! General B.S. (Most Vegas Games)
If possible, surrender 7,9 and 6,10 against dealer's 9,10,A otherwise hit
Always split 8's (unless dealer hits soft 17, then surrender 8,8 against dealer's A--usually in 6 to 8 deck game)
7,9 and 6,10 against dealer's 2 thru 6, stay
7,9 and 6,10 against dealer's 7 or 8, hit
Soft 16 always hit but double against dealer's 4,5, or 6

A three or more card 16 against dealer's 10 that includes a 4 or 5 you can stay where you normally hit but the difference in expectation is very minimal.


LOL Cindy, Laughing Out Loud

smarty pants sigh

Cindy

 

[TOC]

Hey, when someone pointed out that I should have hit on a soft 18 vs. a 10, I didn't get defensive, I can man up and admit when I'm wrong...

Because when you're wrong, you're wrong... and staying on a 16 versus a 10 or A is the wrong thing to do. Doesn't matter if you hit 3 times on 16 and bust each time - hitting in that situation is statistically the right thing to do every time.

You are correct, my bad. I don't know what I was thinking, for some reason I was looking at 16 and not thinking that all you could see was the 7. I stand corrected, sorry about that. A 6 would have been a different story..

 

[aka23]

yw, btw,to clarify, that 1/30,000 number is the chance of winning exactly 5 hands out of 26. The more important number is probably the probility of winning 5 hands or less, which is about 1/24,000.

Treating it as a binomial chance (either win or don't win), the chance of 5 of fewer wins out of 26 hands is about 1 in 90... not 1 in 24 thousand. It is not beyond normal variance, especially considering that optimal strategy was not used for all hands. The "Are My Results Fair?" Calc/Sim in my signature may or may not be relevant, depending on how close your bet size was to fixed.

 

[aka23]

You are correct, my bad. I don't know what I was thinking, for some reason I was looking at 16 and not thinking that all you could see was the 7. I stand corrected, sorry about that. A 6 would have been a different story..

16 vs 10 is close enough that optimal strategy depends on the specific card composition of your hand. With 2-card 16, hit has higher EV. And with 3+ card 16, stand has higher EV. If you be even more precise, use the rules listed below for 3-card 16 vs 10s with multi-deck BJ instead of always standing/hitting. The lower number rules override the following rules.
1. Any hand with a 5 -- Stand
2. Any hand with a 6 or 10 -- Hit
3. All other hands -- Stand

 

[DaveG39]

Treating it as a binomial chance (either win or don't win), the chance of 5 of fewer wins out of 26 hands is about 1 in 90... not 1 in 24 thousand. It is not beyond normal variance, especially considering that optimal strategy was not used for all hands. The "Are My Results Fair?" Calc/Sim in my signature may or may not be relevant, depending on how close your bet size was to fixed.

I think you'll see I corrected my 1/24k in a later post, but only down to about 1/2500. I'd be interested to see the math behind the 1/90.

 

[aka23]

I think you'll see I corrected my 1/24k in a later post, but only down to about 1/2500. I'd be interested to see the math behind the 1/90.

One simple way to get numerical results is to use a binomial calc or Excel, entering the # wins, # hands played , with # chance of event. A good binomial calc is at Old / Expired Link . This page also summarizes the math behind the results. The 1 in 90 chance I listed is based on chance of 5 wins in 26 hands. However, reading the full thread, I see that the 26 hands is with ties removed. If you change it to 5 of fewer wins in 30 hands, then I get 1 in ~400... still within reasonable variance.

 

[DaveG39]

One simple way to get numerical results is to use a binomial calc or Excel, entering the # wins, # hands played , with # chance of event. A good binomial calc is at Old / Expired Link . This page also summarizes the math behind the results. The 1 in 90 chance I listed is based on chance of 5 wins in 26 hands. However, reading the full thread, I see that the 26 hands is with ties removed. If you change it to 5 of fewer wins in 30 hands, then I get 1 in ~400... still within reasonable variance.

I was leaving out ties in my calculations because no money changes hands, and, therefore, would seem irrelevant (sp.). However, if you treat ties as technical losses ("non-wins"), then yes 1/400 is correct. Reasonable though? Isn't .05 (1/20) and above considered reasonable, stats-wise? Then again, with a sample this small, the margin of error would be huge.

 

[aka23]

Reasonable though? Isn't .05 (1/20) and above considered reasonable, stats-wise? Then again, with a sample this small, the margin of error would be huge.

In stats, p-value varies depending on what you are trying to show. 0.05 might be appropriate for estimating whether certain experimental variables are correlated, but it is not rare enough to show unfair software, as questioned in the first post of this thread. Many people in this thread have played more than 20 sessions of BJ with Playtech software, so many are expected to have seen a result with odds rarer than 0.05 in a random distribution. Instead, you'd need a far rarer result (or combination of results) that should hardly ever occur in a random distribution. This is what I mean by "within reasonable variance".