If you've done a little research about blackjack strategy then odds are you've noticed the term "deck penetration." What is deck penetration and when is it useful when it comes to blackjack strategy?

Deck penetration is the term used to describe the percentage of cards that has been dealt before the dealer reshuffles the cards. For instance, in a single-deck (52 cards) game of blackjack where 34 cards have already been dealt the deck penetration is 65%. In other words, the dealer has dealt out 65% of the cards in the deck.

Deck penetration is not very important to basic strategy players. However, it is extremely important to card counters. When counting cards, the larger the deck penetration percentage the better because more cards have been dealt out and "counted", meaning that the count of the cards that remain in the deck will be more accurate.

Interestingly enough, if you are not a card counter than a low penetration could actually be better for you. The more often the cards are shuffled, the less games can be played, meaning that when you gamble at a low penetration table you'll have less opportunity to lose money. However, if you aren't counting cards and are only practicing basic strategy then ignoring the deck penetration won't have much of an effect on the outcome of your game.