Blackjack rewards skill more directly than almost any other casino game - from the fixed, mathematically correct plays of basic strategy through to advantage-play techniques like card counting. Wonging, deciding exactly when to sit down and stand up based on the count, is one of the best-known of those techniques, and a good starting point for understanding how (and why) advantage play works - and why most of it is built for a physical casino floor rather than an online one.
Basic strategy - the mathematically optimal play for every hand versus every dealer upcard - is the foundation, and it alone gets the house edge down to roughly 0.5-1% depending on the table's rules. Advantage-play techniques like card counting and wonging can push the edge in the player's favor on a physical shoe, but require real skill and don't carry over to most online or live dealer formats.
It depends what you're optimizing for - counting can shift the odds in a player's favor on a real, hand-shuffled shoe, but it takes real practice, only works on physical casino floors with adequate shoe penetration, and most modern live dealer tables use continuous shuffling machines specifically to neutralize it.
Basic strategy is a fixed set of correct decisions (hit, stand, split, double) for every possible hand, based purely on your cards and the dealer's upcard - it doesn't change hand to hand. Card counting layers on top of that by tracking which cards have already been dealt, adjusting bet size and occasionally strategy based on how favorable the remaining shoe is.
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