One of the things that is usually misunderstood is that you need to be a mathematical genius to count cards. This is a completely wrong thing to believe. It's not like this at all. All you really need to count cards is the ability to count up to plus or minus twelve or so... by ones even in a multi-deck game.
When in a deck is a limited number of cards valued 2 through 8 the players advantage is bigger. When a deck has a shortage of cards valued 9, 10, and Ace, the player is at a disadvantage. So, if a player could know when the deck is rich in 9's, 10's and Aces, he could choose to bet more money because the deck is favorable for him. Changing the basic strategy play when is more advantageous for him a player can increase his odds of winning a particular hand.
The card counting system has some different systems. One of them is the the "Five Count" system and the basis of this system sounds something like this: through mathematical computation, it was determined that the card that has the most influence on the deck being in a favorable condition (for the player) was the five. When the deck is low in fives, the player has a higher advantage than if it's sparse in any other card. Logic dictates that, for a very simple card counting strategy, simply keep track of the fives.
One of the most used card counting systems is the the high/low (also called the plus/minus) point count. As you can see from the small chart to the right, a plus value is given to low cards, and a minus value is given to high cards. Notice that seven, eight and nine have a value of zero. This is because their overall effect is negligible, as compared to the others.
PLUS (+1) | MINUS (-1) |
2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | A |
1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 1 | 1 |
There are 20 cards in a deck that are valued +1: two through six. There are 16 ten value cards and four Aces in a deck (20 total) that are valued -1. The remaining 12 cards (seven, eight and nine) have a value of zero. At the end of a deck the count should be zero. (If you enter a game mid-way between the deck or shoe, flat bet until the cards are shuffled. Once the cards are shuffled commence counting from zero.)
Off course now you will be wondering how can you use this system applied only for a one deck game, when usually blackjack is played with 6 or 8 decks. The answer for you is simple. As i explained you the basic of this strategy, in a game with 4, 6 or more decks you need to calculate a 'true count' from your running count, based on the number of decks that appear to be remaining in the shoe. The true count has the following equation:
Divide your running count by the number of decks left. Say you have a running count of +6, and there seem to be about 2 decks left, your true count is 6 / 2 or 3. If your true count is three, you should bet 2 times your base amount.
As you can see, it's not important how many decks are used in a blackjack game. This system is simple, all you need to do is to have a good eye at estimating the number of decks that are left in the shoe. Here's a tip for you regarding to this matter: the thickness of a deck of cards is roughly five-eighths of an inch.
Also, if you have trouble keeping the count straight in your head, try using your chips to jog your memory. After every hand tally up the net count and update the running or true count by rearranging your chips.