I don't know, if this is going to be effective online though, of course in a landbase casino, you can try this trick and obviously it will work and perfectly legal. But in online casinos, we don't know how the cards are shuffle. In a traditional base casinos, you can see in the beginning how the dealer shuffles x amount of decks of cards and then put in it shoe.

For online we don't see that, and then there's the element of RNG (random) that is on their side. They can shuffle every x deal, or not. So I don't think the card counting will be effective in online games.