If card counting in blackjack is just keeping track of high cards vs low, does that mean if I could remember all the different cards used (i.e. how many 5s, how many 7s) I would be really good at blackjack?

Question

This would break online casinos because you could easily do that with electronics. Assuming the casino itself is playing fair.

If you could perfectly keep track of how many of which cards are left in the decks, and everytime make the most mathematically sound bet, would the house still have an edge?

(I assume the correct answer will start off saying I don’t understand how card counting works – fair enough, but what about the basic explanation of it did I misinterpret?)

In: Mathematics

Answer 1

Usually casinos play with multiple decks and that makes it much harder, and they don’t run the whole deck down until the end. So they’ll shuffle 5 decks together and then take a plastic indicator card and slid it into the deck somewhere randomly, then when they reach the plastic indicator, they either reshuffle the whole entire 5 decks again or they get new fresh packs of cards (then they punch a hole into the used decks and sell them to you at the gift shop!).

So counting cards becomes pointless because there are 5 decks and you have no idea where they stop playing, which leaves roughly half the decks unplayed … and you can’t account for what’s in the playable first half of the deck.