Single Deck Blackjack

Single deck blackjack is a game in which a single standard deck of 52 playing cards is used, as opposed games that deal from a shoe of four to eight decks. Compared to the figures for a single deck game, a multi-deck game seriously handicaps your play by a factor of 0.35% for two decks, 0.48% for four, 0.54% for six, and 0.58% for eight.

Blackjacks, which pay 3:2 (a payoff of £3 for every £2 wagered), occur more frequently in single deck blackjack games than in multi-deck games. To illustrate this, let’s say your first card is an Ace. On a single deck game, 16 of the remaining 51 cards, or 31.37 percent, are the face or 10-value cards that would complete your blackjack. In a six-deck game, 96 of the remaining 311 cards, or 30.87 percent, would give you your blackjack.

If you were to play 100 hands per hour at £5 per hand, each -0.1% of additional handicap would cost you approximately 50p per hour. Playing on a game with two decks versus a single deck will cost you an extra £1.75 per hour, with each additional deck prying deeper into you wallet.

Unsurprisingly, stumbling upon a single deck blackjack game today is a rare occurrence, unless you come across a casino that advertises “Back by popular demand, Single Deck Blackjack.” But even is you find such a casino you should exercise caution, because the table may have the fatal notice: “Blackjack Pays 6:5.”

In a conventional blackjack game, a blackjack typically pays 3:2. If you bet £10 and get a natural, you'll be paid £15. However, at these new 6:5 games, a £10 blackjack gets you only £12. Despite the fact that the game is played with a single deck, this one little rule change – inspired by Saint Barnum – dramatically increases the house advantage.

This new single blackjack deck game has been very successful for the casinos because the uninformed player has been told over the years that single deck blackjack is a better game than the shoe games that are now prevalent on the casino floor. But by accepting blackjack payouts reduced from 3:2 to 6:5, a generosity you may not have intended, you are giving the casino a 1.39% advantage. Compare that to an 8-deck game where the house edge for a basic strategy player is a much more civilised 0.58%.

So what’s the difference between the two in actual cash terms? For a £10 player playing perfect basic strategy at 60 hands per hour, the expected loss on an 8-deck shoe is £3.50 per hour. The expected loss for the same player on a 6:5 single deck game is £8.35. That’s a significant difference.

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