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

As others have said, online casinos can shuffle very frequently to negate this. Aside from that, using technology is not allowed, so even people legitimately counting with just their brain have had earnings refused from online casinos because they were suspected of using a machine aid.

I would also point out that card counting systems are actually even easier than keeping track of how many 5s, 7s, etc. have been played, because keeping a count for more than two values at a time is really difficult in a casino setting.