Blackjack event probability calculation help

[tiltboy]

I was trying to earn a bonus at Intercasino playing multihand blackjack earlier this week and experienced what I percieved as a pretty bad BJ beat and was wondering if someone here could tell me how to calculate exactly how bad it was.

I played 5 handed at $1 a hand and played 210 hands total (not counting splits and double downs) before I lost my bonus money and quit. During that time I was dealt 5 blackjacks and the dealer was dealt 7. If I remember correctly a blackjack should be dealt approximately every 20 hands when playing an 8 deck shoe. That would mean the dealer should have been dealt only 2 blacksjacks instead of 7 and I should have been dealt 10 instead of only 5.

My stat skills are a bit rusty so I was hoping someone here could point me in the right direction. Thanks for any help.

[crockpot]

well, at least you calculated your own blackjacks about right.

tough break, but you'll bounce back.

[Webster]

Well - I'm not sure why you would play 5 $1 hands to get a bonus and I can't help you on your stats - YET

But I have a pretty nifty excel spreadt sheet for us Bonus Whores that'll tell you exactly what you need to do that includes Standard Deviation at all levels.

Just enter Purchase, Bonus #X and so forth - it's sweet.

AS for your results - you had a bad run but not unexpected at all - WELL within normal fluctuation.

E-mail me
Grinder2@charter.net

[tiltboy]

[ QUOTE ]
Well - I'm not sure why you would play 5 $1 hands to get a bonus and I can't help you on your stats - YET



[/ QUOTE ]
You need to bet the bonus amount 20x to be able to withdraw it at Intercasino. I was trying to minimize variance by spreading to 5 x $1 hands. Do you have a better suggestion?

[MicroBob]

my understanding is 1 in every 21 hands on a 6 or 8-deck shoe.
yeah, you were on the minus side of the SD on that little run.

as a BJ dealer i've had runs where i've dealt myself 5 or 6 BJ's in a single shoe....or i've dealt one specific player 3 BJ's in a row or 4 out of 6 or something like that.

one time, i had 6 players at my table, and i dealt BJ to 5 of them. it was at a $3 table though so the casino didn't exactly lose their shirt on that one.
play or deal long enough and just about anything can happen.

one of my faves....i was dealing single-deck and had an ace as my up card....turn over the hole-card, another ace. hit my 2-or-12 and get the 3rd ace. of course, the 4th card was the final ace. yup, 4 aces right in front of me, guess i should have played poker that night.

on the next hand, i had a 10 as my up card...so i officially knew i was okay to not bother checking if there was an ace as my hole-card.

after one of the types of runs you had it's common to wonder if the online-casino is rigged....but it doesn't seem to be too far off anything that commonly happens in B&M blackjack.

[CORed]

[ QUOTE ]
I was trying to minimize variance by spreading to 5 x $1 hands. Do you have a better suggestion?

[/ QUOTE ]

Actually, to minimize variance, you are better off playing 1 hand at a time (at the same $/hand). When you play multiple hands against the same dealer hand, there is covariance, because the results of all 5 hands are partially dependant on the dealer's hand: If the dealer gets a blackjack, all 5 lose. If the dealer busts, all the hands that didn't bust win. If the dealer gets 18 or 19, usually some will win, some will lose. 5 hands at a time for $1 each is lower variance than 1 hand of $5, but considerably higher variance than 5 hands head up at $1 each.

[Webster]

Here is a screen shot of my little Excel spread sheet for BJ Bonus Whoring.

http://webpages.charter.net/grinder2/GrindersBJBonus.htm