The more changes to the original rules of blackjack usually mean that the house edge is increasing. When the blackjack rules allow players to double after splitting the casino loses a bit of their advantage. Generally, the more restriction on the players making this wager the higher the house edge for the casino. 6-deck- Bally’s has a regular 6-deck game (not Spanish 21) that has the same rules as the Fitz; Hollywood allows doubling after splitting; Resorts have dealers stand of soft 17 and doubling after splitting.

If some kind of respectable double is required, and your initial wager is less than 35 times the double wager, then you should stand on soft 18 vs. The value of being allowed to double after splitting aces is 0.08% if double for less is not allowed, and 0.15% if it is allowed. Blackjack Side Bets; Introduction to Card Counting.
Blackjack pays 3 to 2. Dealer will stand on seventeen (17), hard or soft. Original hands may be split once. Aces may only be split once and will receive one hit card. No double after a split. Double Down is only allowed on nine (9) ten (10) and eleven (11). Double on Blackjack is allowed. Insurance is allowed.

As we have discussed before, the number of decks with which a Blackjack game is played is essentially a rule unto itself and impacts the House Edge of the game accordingly. In the event that all other rules are equal, then the more decks a Blackjack game has, the greater the House Edge will be against the player, which is to say that there will be a lesser return to player.

In the case of card counting, multiple decks are something of a boon and a bane to card counters. Granted, all other things equal, the card counter will generally get more favorable opportunities against a lesser number of decks and will buck a lesser negative expected value while waiting for positive counts, (because fewer decks is generally good) but all other things are not equal and games considered, ‘Highly countable,’ are often subject to greater scrutiny from the pit as well as the eye in the sky. Even though it is dead wrong, there are still pit bosses out there who believe, ‘A six (or eight) deck game cannot be counted.’

Double deck games, either way, certainly can be counted. However, for the basic strategy player, double deck games offer fewer opportunities than single-deck games to make decisions based on the, ‘Deck composition,’ and it is for that reason that double deck has a greater house edge.

When we compare the rules of double-deck variations, we are going to use what I will term a, ‘Control Game,’ and that control game will have the following rules:

Soft 17: Dealer Hits
Double After Split: Yes
Double On: ANY
Player Can Resplit: Twice to Four Total Hands
Resplit Aces: No
Hit Split Aces: No
Dealer Peeks: Yes
Surrender: Yes
Blackjack Pays: 3:2

With this, ‘Control Game,’ the House Edge with Basic Strategy is 0.39702%, if we compare that to single-deck with the exact same set of rules, the single deck game would have a House Edge of 0.12144% for a difference of 0.26928% added to the House Edge for the double-deck game.

This is not only because of fundamental hands/decisions being more powerful for a player in a single-deck game due to the effect-of-removal (cards coming out of the deck) but also because there are some plays that get made as a result of effect-of-removal in a single deck game that do not happen in a double-deck game, such as doubling an eight against a dealer showing five/six in a single-deck game. You would not do that in a double deck game.

The Rules:

While double-deck Blackjack gives the player an opportunity to play deck composition strategy, it does not grant the same opportunities that a game such as single-deck often will. Deck composition strategy is basically what card-counters do, except they can often do this with games of several decks and are doing more than making decisions based only upon the number of cards that have come out/are showing in one hand. While such decisions still come up in double-deck Blackjack for the savvy player, they are nowhere near as common as they are in a game of single-deck.

Soft 17

The first rule change we will examine is whether or not a dealer hits or stands on soft-17, which is any hand that adds up to seventeen with the Ace counting as eleven. In other words, A-6 would be an example of a Soft-17, A-2-4 is another example and A-2-2-2 is yet another. These types of hands actually come up slightly more frequently in a double-deck game as opposed to a single-deck game (and even more frequently in games of greater decks) simply because the effect of a card, say a deuce, being removed on the probability of getting yet another deuce is greater with a fewer number of decks.

The rules for our control game assume that the Dealer Hits on a total of soft-17 whereas it would be beneficial for the player for the dealer to stand. While it may seem antithetical that a player benefits by the dealer standing on what then becomes a completed hand, it is important to remember that the player has already acted and that hitting a Soft-17 gives the dealer several opportunities to improve the hand with a nearly equal number of opportunities to keep it the same as if the dealer had stood. (i.e. turning it into a Hard-17 with a ten)

For example, if two cards, an A-6 come out of the deck giving the dealer a Soft-17 and the dealer hits, here are the possibilities for the very next card:

(31/102)-The dealer improves his hand to a 18-21 by way of another Ace, or a two, three or four. The four, of course, would give the dealer an unbeatable twenty-one that can only be matched for a push if it matches the player’s total.

(32/102)-The dealer draws a ten-card that results in a Hard-17, which is what the dealer would effectively have even if he stood on soft-17.

(39/102)-The dealer draws a five, six, seven, eight or nine, which are arguably the worst cards for the dealer because the hand is incomplete and busting is now possible. Even with that being the case, though, assuming the player plays perfect strategy based on the rules, the player will have a hand that beats (or pushes) seventeen enough of the time that the dealer is better running this risk.

One might wonder: But, aren’t 39, ‘Bad cards,’ more than 31, ‘Good cards,’ what gives?

The answer to that is simply that the, ‘Good cards,’ absolutely make a hand that is better than what the dealer had if forced to stand on the Soft-17, and the, ‘Bad Cards,’ are not necessarily a death sentence for the dealer. The dealer could draw a five to a Soft-17, for example, giving the dealer a hand total of 12, then the dealer could draw a nine for a total of 21, which can only be pushed by the player.

There’s no need to believe me, though, you could simply look at our blackjack strategy engine:

And you will see that, with Basic Strategy, based on our control game, when we switch it to force the dealer to stand on Soft-17, the house edge is reduced to 0.20416%, which is a difference of 0.18656% in favor of the player. In other words, this one rule change cut the house edge nearly in half as compared to our control game!

Double On Any Two Cards

The next rule that we must take a look at is the doubling rule, some casinos will allow a player to double on any two cards the player likes, whereas other casinos only allow doubling on hand totals of 9-11 and others still only allow doubling on hand totals of 10-11. While a single deck game is the only time a player would double on hard eight (absent card counting) there are still a number of soft hands that do not otherwise total 9-11 on which a player would double in the double deck game.

For example, a player would double a soft 13-19 against a dealer six, and only the A-8 technically equals nine (in terms of the hard hand), the player would double soft 13-18 against a dealer five, a soft 14-18 against a dealer four, a soft 17-18 against a dealer three and a soft 18 against a dealer deuce. With exception to the soft nineteen (which, again, would also be a hard nine) against a dealer six, all of these plays would be gone if the player could not double on anything.

Our control game allows for doubling on Any

Blackjack Rules Split Double