Odd hands

I was playing Casino Verite Blackjack with a two deck game and 75% penetration with about 1 3/4 deck's left, and I get a pair of eights, I split, get another eight, I split again, another eight, I split for the last possible time; So I have four eights down, I get a queen, stand for that hand, get another queen, stand, another queen, stand, and yes for the last hand I get another queen. Anybody familiar with math know the odds for that? (forgot to check the suits)

Anyways, I was wondering what are the wierdest or rarest hands you people have gotten playing in casinos (or computers).

(oh yeah, the dealer got twenty)

actually this should'nt be so rare in casino's with a new dealer, right? I mean if the dealer shuffled the decks, just a clump of 8's got together with a chunk of queens of either deck.

new221b,

Odds of receiving four eights followed by four queens in double deck are given as follows:

Odds = (8/104)*(7/103)*(6/102)*(5/101)*(8/100)*(7/99)*(6/98)*(5/97) = 2.7176495316400147463305237159598e-10

Here, the (8/104) represents the 8 eights present in 104 cards. After receiving one eight, you have 7 more in 103 cards: thus, the second factor is (7/103). By similar reasoning, the next two factors represent one of the 6 remaining eights in 102 cards, and one of the 5 remaining eights in 101 cards. The last four factors represent similar terms for the queens, except that the total number of remaining cards keeps decreasing.

Hope this clears it up for you!

Dog Hand

That is a cool hand. That is messed up about the dealer 20 :)

Dog's calculation is better, but for fun I just ran the numbers based on a fresh shuffle. Hard to calculate exactly without knowing the cards that have been played. What I came up with on a fresh shuffle on 8 decks was .0000000008889 for your hands. Either way it is calculated, that is a longshot :)

We're talking about a virtual game here. I have more faith in Norm's abilities as a programmer than just about anybody's, but there's always a remote chance something is amiss. That chance, I think Norm would agree, is "significantly" higher than .0000000008889. :)

I don't know if this is rare, but I received an 8 card 21 recently playing CVBJ

Best, Jim

I think the odds are approx. 1.1m/1

We're talking about a virtual game here. I have more faith in Norm's abilities as a programmer than just about anybody's, but there's always a remote chance something is amiss. That chance, I think Norm would agree, is "significantly" higher than .0000000008889. :)

That would be a generally good bet. But, probably not in this case. CV has three methods of shuffling - real casino shuffle, biased shuffle and random shuffle. If he was using the random shuffle, the odds of a pattern emerging as an artifact of pseudo-randomness is ridiculously unlikely as the the shuffle routine is quite unusual. In fact, the cards are not shuffled but pulled randomly from the deck. Poor random number generators can create all manner of artifacts. But the incident described is difficult to imagine. And if it were an artifact, it would probably have been reported previously. Now the biased shuffle is another matter.

Also, .0000000008889 is the wrong number to look at. Dog Hand's calculation is correct - as far as it goes. But, it only includes this one odd possibility. Had new221b received four Kings he would have still posted. Or, four Treys with the Queens. So yes the odds of this one exact unusual event may be .0000000008889. But, what are the odds of realizing any equally unusual event worthy of comment? And what are the odds of thousands of users realizing an equally unusual event over their usage history?

Deal yourself 8 cards. Now calculate the odds that you will ever see those eight cards dealt in that order again. Wow, you just saw an extremely rare set of 8 cards!

Dr 21

I was trying to come up with a simple way of saying exactly that. You nailed it. Every time you shuffle a deck, it is put into a highly unlikely state.

I'll go out on a flimsy limb and suggest that we should probably limit the set of possible variations to those hands in which a CVBJ user would actually be likely to split three times against a "ten". Therefore, the "Treys" variation isn't really valid, is it? ;)

Although it's probably not a possibility in CVBJ, I was thinking more along the lines of an error in a sub-routine responsible for DISPLAYING the most-recent picked card, not an error in the sub-routine that actually randomly picked the card in the first place. A Boolean which flagged the hand as reaching its maximum number of splits (SP3?) could prompt the jump from Eights to Queens, in theory. Of course, in such a scenario, an error like the former would be far more likely to display four Eights of the same suit, followed by four Queens of the same suit. There are all sorts of ways the hand could pop up without being a "valid" hand, but you're right: If it were a problem with CVBJ, it most likely would've been reported by now.

Although I agree that the chances of a goof of this nature are incredibly remote, the thrust of my post was that the chance might actually exist somewhere in the one-in-a-hundred-million range. That would make it far more likely than the actual "real" hand itself (or any of the similar hands you propose).

Still, I get your point. :)

Therefore, the "Treys" variation isn't really valid, is it? ;)

Assume against a Six. Still as 'unusual' and 'postable.'

I was thinking more along the lines of an error in a sub-routine responsible for DISPLAYING the most-recent picked card

CV is rather odd here also. CV doesn't have stored card images. It builds a card a pip at a time in video card memory each time it displays it. Rather difficult to imagine getting stuck on a card. More likely it would just print a non-existant card. But I also get your point.

norm

I can't find where to look to see what type of shuffle I'm using (real casino shuffle, biased shuffle or random shuffle). Does this have something to do with CVShuffle? If so what shuffle is used if you don't have it? (i don't have it)

If you enter the program and it says "Shuffle Randomized" then it is using a real casino shuffle. To get back to a random shuffle, use TOOLS-CVSHUFFLE and turn off the shuffle option at the bottom of the screen. Biased shuffling occurs if you have changed the biases on the SPEEDS tab of OPTIONS-SETTINGS.

Nice! This is not quite as rare, but I was recently playing single deck in a casino and got 4 blackjacks in one shuffle. That's about 1 in 1.8 million if I did my math right (though I give that an even lower chance).

But it was a double deck game in a casino. Lots of aces and 2's in a very negative count. The dealer ended up with a 5 or 6 card 20.