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

Back in the day, yes. There are numerous movies and documentaries on the subject of how successful counting cards was, and how much casinos hated it (to the point of having their security assault counters to the point they gave up the info on how they were winning) and developed counter measures against it.

Card counting was absolutely a thing. But only for in-person casinos.

Online, it’s almost impossible. Every hand comes from a freshly shuffled deck with every card in it. There can be no counting because there is nothing being lost from the source deck itself. It’s always fully stocked. Unless you’re in a game with real-world deck rules (like they have 8 decks worth of cards and reshuffle them after they’re through 40-60% of the cards).