Penetration ( blackjack)

How deeply into the pack or shoe a dealer goes before shuffling. In CBJN, penetration is expressed as number of decks left when the shuffle point is reached. Penetration is sometimes expressed as the number of decks dealt out of the total (eg 5½/6, which means 5½ decks out of six) or as percentage of cards dealt out (e.g. 60%, 75% etc).