blackjack

The house edge in blackjack is ~0.5% with basic strategy. Card counting tilts the odds by tracking the ratio of high to low cards remaining in the shoe.

Hi-Lo: +1 for 2–6 · 0 for 7–9 · −1 for 10,J,Q,K,A

A positive running count means more high cards remain, favoring the player. True count = running count / decks remaining — bet more when it's high.