The penetration of the deck is a significant value, especially for counters (see counting cards in blackjack). The knowledge of the penetration gives the player a very interesting advantage because usually, only a few cards remain. If the card counter knows how many low and high cards are left, it can change the bet amount, possibly the game strategy, depending on the situation.
So what is the deck penetration? At the beginning of each game with new cards, dealers put a special card into the deck's shoe. Once all the cards have been played before this inserted card, the decks are shuffled, and all cards are played again. Where this so-called cut card is located shows us the deck penetration.
The higher the penetration, the better the conditions for players
Many years ago, there was only single-deck blackjack. Dealers handed out the entire package until the end. Which is very good for players, but unfortunately that is a thing of the past, because the casino management knows well what the advantage is for players.
Players would like the dealer to put a card cut somewhere around 65% to 70% of the deck, for any game. It does not matter if it is a single-deck or a multi-deck version of blackjack. If this is not the case, the player will not get into some favourable situations, which can then result in a significant advantage on the casino side.
Do not play a game with a low penetration value
I even visited a casino where the cut card was given up to half of the six decks. And let's face it. I did not last long in this game, because the penetration, in this case, was only 50%. If the game does not have a good penetration value, do not hesitate and move to another table or change the casino straightaway.
At the end of the article, it is a good place to mention that the deck penetration is a thing only in land-based or live casinos. All online versions of blackjack use single deck, but is shuffled after every hand.