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-   -   BJ down swing- want to find out how rare of an event this is... (http://archives2.twoplustwo.com/showthread.php?t=173093)

 bholdr 01-08-2005 02:47 AM

BJ down swing- want to find out how rare of an event this is...

ok so i'm playing blackjack at five bucks a hand, everything going cool... then the cards go cold for a couple hundred hands. not just cold, but 'holy crap gimme something to smash i hate this damn game i'm gonna quit forever, i swear' cold. i keep accurate track of my hands, and here it is:

212 bets in about 195 hands (i use 54 bet intervals to record my bonus clearing progress)
first interval -12 bets
second interval -18 bets (yuck! lost two doubles and both ends of a split in this one, and pushed a BJ)
third +1 bet
fourth -15 bets
=
a -44 bet swing (220\$, my whole bonus and then some)

in an overall session of 636 bets, @ 590 hands
and this is at downtown vegas rules BJ, house advantage .36%, my play was nearly perfect (i may have made one or two mistakes, max, i still fail to double a soft 14 into a five sometimes, or mis-click the mouse etc).

how do i calculate the SD for these odds and session lenghts? is there a downloadable spreadsheet that will do it for me?

i don't often post in the odds forum, forgive me if this is an annoying or O/T post, but i'd really like to know how often i'll have to deal with this.

 pzhon 01-08-2005 03:44 AM

Re: BJ down swing- want to find out how rare of an event this is...

Without determining what criteria you used to separate this streak from the rest of your session, you can't say how unlikely it was. Why didn't you just talk about the one set of hands where you lost 18 bets? Did you not include other sets of 54 bets on either side because you won?

If you had played only these 195 hands, you would be down about 2.7 standard deviations (assuming a standard deviation of 1.17). Keep in mind that it is much more likely that you hit a bad streak at some point than that you get that streak in a prespecified set of hands.

If you want to collect useful data, determine what you are looking for before you start looking, or stick to very simple patterns.

I lost 21 hands of blackjack in a row (no ties, total loss 25 units) at one online casino. I had the casino verify the streak after 20 hands. However, I have played enough hands that it really wasn't much of a surprise to hit at least one losing streak of that length. By the way, I'm ahead by a lot at that casino despite the streak.

 gaming_mouse 01-08-2005 06:38 AM

Re: BJ down swing- want to find out how rare of an event this is...

[ QUOTE ]
By the way, I'm ahead by a lot at that casino despite the streak.

[/ QUOTE ]

pzhon,

I like your posts, so I was just curious why you play online BJ. Isn't it a guaranteed loser in the long run? Or is it just for fun?

 bholdr 01-08-2005 07:04 AM

Re: BJ down swing- want to find out how rare of an event this is...

PM coming to you.

 bholdr 01-08-2005 07:18 AM

Re: BJ down swing- want to find out how rare of an event this is...

thanks a lot for the reply. told you i'm a probability noob.

it was seperated, more or less, at random. to count the number of hands that i play, i hold a deck of cards in my left hand as i operate the mouse with my right, and drop one for each bet i make. it's easier than counting in my head or on paper. (and after trying for a few hours to count in my head, i found myself counting nonsensical things all the time. steps, cars that drive by, etc. [img]/images/graemlins/crazy.gif[/img])

i the sets that i mentioned were #s 4,5,6, and 7 in a total of 12 sets. so the start and finish times were not dependant on the start or finish of that bad streak. in fact, i think i won like the last seven hands in a row of the last set.

set 1: +1.5 bets
set 2: -5 bets
set 3: +4 bets

then it all goes to hell,

the rest was pretty even.
I gave only the sets that concerned me because i was wondering what the odds of a swing like that happening in a random set of about 200 hands (212 bets in this case). Btw i cleared that bnus in the next session i played for a 56\$ profit in two hours at about 250 hands/ hr. that partiicular site has slow software and i was eating dinner and then watching the simpsons at the same time. when i am really in a rythym, with fast software, i push 600 h/hr with about 1 mistake/100 hands.

any more info on odds calculations, even a good textbook recomendation, would be much appreiciated. the more i gamble, the more i wish i had payed attn in math class. [img]/images/graemlins/tongue.gif[/img]

thanks again, pzhon!

 bholdr 01-08-2005 07:27 AM

oh, you poor bastard....

i just took a look at that link you posted. i know it's only a matter of time until i get one like that too. (here's to hoping it's up the first time)

Bholdr [img]/images/graemlins/smirk.gif[/img]

 pzhon 01-08-2005 06:13 PM

Re: BJ down swing- want to find out how rare of an event this is...

[ QUOTE ]
I was just curious why you play online BJ. Isn't it a guaranteed loser in the long run?

[/ QUOTE ]
I think I'm ahead about 5 standard deviations overall. I like the way so many online casinos offer \$100 to wager an amount on blackjack such that I give back about \$15 in house advantage, net \$85+-200 for under an hour. This was the fastest way for me to build a poker bankroll without adding more of my own money. When I play poker, I often have 3 tables going in 3 quadrants, and blackjack in the 4th quadrant.

See www.onlineblackjackguide.com , where I am the poker moderator. There are also discussions of online casino bonuses in the Internet Gambling forum here, and in the casino forums of www.bonuswhores.com .

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