This article is part of our Beating the Book series.
Roughly 20 years ago, I read Edward O. Thorpe's book, Beat the Dealer. It described a card-counting system for blackjack wherein any card 2 through 6 was given a plus one, 7 through 9 a zero and 10s and aces a minus one. The idea was to bet small when the count was negative (lots of low cards still available in the deck(s)), and bet bigger as the count got more positive (lots of 10s and aces available.)
This works because it undercuts the house's central advantage over the player: that when the player busts, and the house also busts, the player does not get his money back. For example, if you have a 15, and the dealer is showing a 10, basic strategy dictates you hit. Should you get a 10 and bust, the dealer will sweep away the chips you bet. Suppose the person next to you has a 20, sticks and the dealer turns over his hole card, showing a six, hits, draws an eight and busts. You do not get your lost chips back.
In summary, if you both bust, the house wins. That is its only advantage over you. You have several advantages over the house: (1) you can split or double down when circumstances warrant; you get 3:2 odds on a blackjack; and (3) you can choose how much to bet on a particular hand. To the extent the deck provides cards that merit sticking, your relative advantage grows. To the extent it