# Blackjack, random number generators

1. Sep 19, 2004

### billy_boy_999

is there a way to 'beat' a random card generator in blackjack with card counting?

a very simple card counting system works by counting high cards against low ones, if i have a count of +9 (high cards likely) with 3 decks left in the shoe i divide by # of decks left and get a +3 'true count'...

the reason this works is that the count will inevitably fall back to zero at the end of the shoe (the sum of all decks is zero, all cards will hypothetically be played)...

the question is this: with a random card generator it is like an infinite number of decks left in the shoe, so i would have to divide my running count by an infinite number, not good for maintaining a high count...but this is not the entire picture because it implies that the count will take an infinite amount of time to return to zero, this is simply not what happens, it takes a little longer but it still returns to zero from time to time...i want to figure out the average number of cards it takes a random card generator to return to a zero count, figuring out what i have to divide my running count against to get a true probability of high cards being played in the future...is there a way to do that?

2. Sep 20, 2004

### HallsofIvy

If I understand "random number generator" which you refer to as "like an infinite number of decks left in the shoe" correctly, then it is also like reshuffling the entire deck after each deal (which typically is not done since it is too time consuming).

Card counting will not work because card counting depends on "that card has already been dealt so it cannot come up again" which is no longer true.

3. Sep 20, 2004

### billy_boy_999

but that it is simply not the case...keep in mind that card counting does work with multiple decks...i'm not concerned with whether or not the jack of diamonds can no longer be played, i'm simply concerned with how many high cards have been dealt compared with low cards...availability is relevant but it's not a matter of eliminating possibilities, its about probability...

here is how the basic hi-lo system works, fyi: every card in the deck has a value, 2,3,4,5,6 are worth +1...7,8,9 are worth 0...10,J,Q,K,A are worth -1...the sum of a full deck is therefore 0...then we simply keep a running count of the value of the cards left...a high positive count means a lot of low cards have been dealt and there is a high probability of high cards being dealt in the near future - this is a palpable advantage...

again, the fact that a certain card can never come up again is not the concern, the concern is how useful is my positive count...that is, if i have a count of +10 does it mean anything? if the count does not return to 0 it means nothing, the sooner it returns to 0 the more meaningful the count is...

if it were as simple as 'the count will only return to zero at the end of the deck' and thus, 8 decks means a period 8 times longer to return to zero, that would be one thing, but the count returns to zero more often than once per deck...what i am interested in is calculating the average period it will take to return to zero with a random number generator...