Blackjack is based decks of 52 playing cards. If you have ever had a statistics and probability course in school, you’ve probably dealt with the probability of drawing one particular card from the deck. Using the same principles it’s possible to determine the odds of winning or losing any particular blackjack hand.

In any casino blackjack, the house has the edge. That means over time, the casino is going to win more hands than the player. Eventually the casino will win. The casino gets this edge primarily because the player goes first. The player has a chance to bust before the dealer.

Basic blackjack multi-deck strategy is designed to minimize the house edge. If you adhere to strict rules regarding what action to take based on the dealers up card and your hand total, you can reduce the house edge to it’s bare minimum. Basic strategy has already worked out which action will statistically be the best action for the player. Basic strategy does not guarantee you will win every hand. But over a long enough period of time you will perform better if you adhere to the basic strategy. Keep in mind that no matter how well you play the basic strategy, the house still has the statistical edge.

Card counting is the next step beyond basic strategy. The dealer must hit below 17. This means that having low value cards in the shoe is statistically beneficial to the dealer. The dealer has an advantage when it is likely that he will draw a low value card. Conversely, the dealer is at a disadvantage when there are more ten value cards in the shoe. The dealer is more likely to bust when hitting below 17. Statistically the player has an edge of the house when there are more 10 value cards in the shoe.

Card counting seeks to take advantage of knowing when there are more ten value cards in the shoe. Blackjack has a “history” in that as cards are played from the shoe they move to the discard pile. So, if you know that more low value cards have already been played, then you know that there must be equally many ten value cards remaining in the shoe. Therefore you know that you have an advantage over the casino. When you realize you have the statistical edge, you raise your bet accordingly. You wager more when the cards are in your favor.

All card counting systems rely on keeping a “running count”. The running count represents the history of the game. Basically, every time you see a low value card played, you add one or more points from the running count. Every time you see a ten value card (or an ace) you subtract a point. A positive running count is signals that more low value cards have been played, and that there are equally many ten value cards in the shoe. In the most basic systems, that’s all you need to do. You need to know when to add or subtract points, and you must keep an accurate running count in your head.

Please note that that “history” of the game is lost whenever the dealer shuffles. All cards are added back into the shoe, so the game starts over. At this point you must start your running count over at its initial value.