Blackjack › Questions › Card counting
Does card counting work with 6 decks?
Yes. Six- and eight-deck shoes are where most counting happens today. You need the true count rather than the running count, the edge per count is a little smaller than with one or two decks, and how deep the dealer deals before the shuffle decides whether the game is worth playing. A shoe cut at 75% or deeper is beatable; a continuous shuffling machine is not.
With basic strategy, the common Las Vegas rules cost 0.53% of the bet at 6 decks, 0.33% at 2 and 0.01% at 1; the count has to overcome that before the player is ahead.
House edge by number of decks
The same rules (dealer hits soft 17, double after split, late surrender, blackjack pays 3 to 2) with basic strategy, from the engine.
| Decks | House edge |
|---|---|
| 1 deck | 0.01% |
| 2 decks | 0.33% |
| 6 decks | 0.53% |
| 8 decks | 0.56% |
Why
More decks mean each card changes the mix less, so the count climbs and falls more slowly and high counts come less often. That is why the running count must be divided by the decks left, and why penetration matters so much: if the dealer shuffles with two decks still in the shoe, the richest part of the shoe is never dealt. The starting house edge is also higher with more decks, so the count has further to go. With a deep cut, a wide bet spread and the true count, a six-deck game gives a counter a small but real edge.
Why the cut card decides
The cut card sets how much of the shoe is dealt. Counters call it penetration: 4.5 of 6 decks is 75%, a good game; 4 of 6 is 67%, marginal; and a shoe cut at half is not worth the time. The count strip in the trainer shows the decks left, and the trainer deals three quarters of the shoe before shuffling.