- A deeper penetration is best for adding edge to the player.
- Any placement that cuts over 50% of the deck is much harder to beat over the long run.
ATLANTIC CITY, N.J. – Penetration in blackjack is how far into the decks the table plays before reshuffling. The cut-card placement determines penetration as players place (an often red) card somewhere in the deck to cut it.
If you’re ever tasked with this at the legal blackjack table, put the cut card as far back as possible. This will help you play more hands during the session, releasing more information about the cards already seen.
- In multi-deck blackjack (6 decks), every quarter of the deck adds about 0.1% edge to the player.
Instead of cutting in the middle, cutting at 80% can almost triple your hourly win rate.
Now, there may be rules about how far back you can cut based on the casino. Still, cutting three of the six decks doesn’t give much data about the cards still in the shoe; so, try to cut all but one deck.
How Penetration Increases Players’ Edge
Knowing how many tens and aces are left in the shoe is getting the advantage from penetration. This gives you a more accurate running or true count while a shallow penetration can have more variance and swings.
In a six-deck game with standard blackjack dealer rules, here is the edge for card counters playing by the book.
| Penetration | Cards Dealt | Edge On First Hand | Average Edge Per Shoe |
|---|---|---|---|
| 50% | 156 | +0.13% | 0.30% – 0.40% |
| 62.5% | 195 | +0.20% | 0.50% – 0.60% |
| 70% | 218 | +0.27% | 0.65% – 0.75% |
| 80% | 250 | +0.42% | 1.05% – 1.15% |
| 90% | 281 | +0.60% | 1.55% – 1.70% |
Keep in mind that many casinos might not allow for a 90% playthrough, nor sometimes even 80%.
In some casino resorts, you might also see the dealer position the penetration in the same spot every time. If this is the case, take note of how far back it is before you sit at the table.