Why counting cards works

Counting cards isn't magic. It's tracking a simple ratio: are there more high cards (10s, Aces) or low cards (2–6) remaining in the shoe? Why it matters: The dealer has to hit any hand under 17. More high cards remaining = more dealer busts. Also, more blackjacks for you (which pay 3:2 instead of 1:1). Each removed low card (2–6) is mildly good for you. Each removed high card (10, A) is mildly bad. Counting systems assign +/- values to track this. Hi-Lo is the most popular system: - 2, 3, 4, 5, 6 = +1 - 7, 8, 9 = 0 - 10, J, Q, K, A = −1 Keep a running total as cards come out. Positive = shoe is rich in high cards = you have an edge. Raise your bet.