Blackjack Card Counting and Deck Penetration

Card Counting

For many blackjack players, basic strategy is enough to keep them happy. But for those who really want to excel in the king of card games, there is more left to be desired. It is for them that card counting was invented.

Card counting a mental exercise in which the player keeps a record of cards as they are played. Some cards are more helpful for the player than the dealer, and other cards are the opposite. By keeping track of what cards are used and what's left, a player can vary their bets so that they wager more when the game is advantageous to them and less when it is disadvantageous. That means bigger wins and smaller losses.

Card Counting Basics

Card counting is not some mysterious ability that only the gifted can accomplish. To count cards, you must first select a card counting system. The most basic is the Hi/Lo system.

The Hi/Lo divides cards into 3 categories:

Favorable: 10, J, Q, K, A Unfavorable: 2, 3, 4, 5, 6 Neutral: 7, 8, 9

These types of cards are assigned numerical values:

Favorable: -1 Unfavorable: +1 Neutral: 0

These values are given because you need to have the high (good) cards to *stay* in the game. If you recall, a deck filled with high cards is good for the player. If it is full of low cards, it is better for the dealer. So every time you see a high card dealt, you count -1. If you see a low card, you count +1. You ignore neutrals.

How to Count Cards

After shuffling, a new deal begins. You start the count at zero, since no cards have been used yet. As soon as dealing ensues, you count. If it is 10, J, Q, K or A that is dealt, you add -1 to the score. If it is 2, 3, 4, 5 or 6, you add +1. Ignore 7, 8 and 9 as if they weren't there.

Here is an example of a card counting routine:

0 ---- Start +1 2 +2 5 +1 J +2 4 +2 7

If the count is very high like +8, it is time for you to wager bigger amounts. On the other hand, if the count is 0 or negative, you must wager the table minimum.

Deck Penetration

Dealers are trained to regularly shuffle the deck or decks in a blackjack game. Blackjack deck penetration refers to the amount of cards that are dealt out before the dealer shuffles them. It is a percentage of the whole deck or shoe (multiple decks). For example, if a double-deck blackjack game has 70% penetration, it means about 45 cards are dealt before a shuffle.'

The deeper the deck penetration, the happier the player engaged in card counting. Imagine if you were counting and just when the game was turning in your favor, the dealer shuffles. That sucks, doesn't it?

Some dealers are taught by casinos in card counting. They may count at the same time that the player is. If so, they may perform what is called "preferential shuffling" or shuffling the deck at no fixed interval, but only when the dealer thinks the deck(s) are favoring the player.

Deck penetration is important only in card counting. To a blackjack player using only basic strategy, it does not matter whether the cards are shuffled at 50% or 90%. Unless the dealer is cheating in some way, the cards will be as random in one case as the other.