Blackjack Switch

Last update: Mar. 27, 2008

Introduction

Blackjack switch is a blackjack variant which allows the player to do what is normally considered a classic cheating manoeuver, trading cards between two hands. The player must make two bets of equal size and is allowed to switch the second card dealt to each hand. Of course nothing comes free, a dealer 22 results in a push and blackjacks pay even money. Currently the game is played at Playtech Internet casinos and various casinos in Las Vegas and Russia.

Casino Royale Rules

I consider these the default rules. They are followed at the Casino Royale in Las Vegas and at Playtech Internet casinos.

• All rules are based on conventional blackjack unless otherwise noted.
• Six or eight decks are used.
• Dealer hits a soft 17.
• The player must make two bets of equal size.
• Cards will be dealt face up.
• Dealer will peek for blackjack with an ace or ten up. If the dealer has a blackjack all player hands will immediatley lose, except a player blackjack will push.
• The player may switch the second card dealt to each hand. For example, if one hand has 5,10 and the other has 10,6, the player may switch the 10 and 6 to have two hands of 11 and 20. The player may also switch cards to form a blackjack.
• Player may double on any 2 cards.
• Player may double after a split.
• Player may resplit up to four hands.
• Winning player blackjacks pay even money.
• A dealer total of 22 will push against any player total of 21 or less. A player blackjack will still beat a dealer 22.

Harrah's Rules

Same as Casino Royale rules, except if the player switches to a blackjack it is treated as a 21-point hand. Six decks are used. These rules are followed at Harrah's in Las Vegas, Reno, and Lake Tahoe.

Tropicana Rules

Same as Casino Royale rules, except:

1. If the player switches to a blackjack it is treated as a 21-point hand.
2. A player blackjack automatically wins.
3. Eight decks.

Russian Rules

The rules in Russia are the same as Las Vegas except as follows.

• Four or six decks are used.
• Player may usually take early surrender, giving up one bet and surrendering both hands. Some casinos do not allow early surrender against a dealer ace.
• Dealer does not take a hole card.
• Dealer stands on soft 17.
• If player switches to a blackjack it is treated as 21 points.

Strategy

The following tables show the basic strategy under the 8-deck Las Vegas rules after the switch decision has been made. The reason for the differences compared to conventional blackjack strategy is the push on 22 rule.

If 6 decks are used the player should double 9 against a 5.

At this time I do not know the strategy under Russian rules.

The switch decision is more complicated. Most of the time it will be obvious. The following tables can be used to determine whether or not to switch in any situation under the Las Vegas/Playtech rules. The player hand is along the left column and the dealer's up card is along the top row. To use the table add the expected values by switching and not switching and play the pair of hands with the greater expected value. An example follows the table.

Example:Hand 1 is Q7, hand 2 is 9J, and the dealer is showing a 2. The player can not switch and have a 17 and 19, or switch and have a 20 and 16. The value of a 17 and 19 is -0.3081+.2264 = -0.0817. The value of a 20 and 16 is 0.4829-.4385=+0.0444. So, in this case, the 20 and 16 is better, so the player should switch.

The switching strategy based on the Las Vegas rules table is only wrong in 548 cases out 100,000, the probability of a mistake is 0.37% and these mistakes would increase the house edge by a negligible 0.0002%. There are about 300 differences between the switching strategies for Playtech and Las Vegas rules, most of them when the dealer is showing a 6, 10, or an ace, but none when the dealer is showing an 8.

Strategy Calculator

My Blackjack Switch calculator, courtesy of Jing Ding, will advise when to switch in any situation. The calculator is based on the Playtech rules and an infinite deck assumption.

House Edge

There are a lot of rule variations out there. Here is the house edge for most of them.

Casino Royale: The house edge is 0.18% with eight decks and 0.16% with six decks.
Harrah's: House edge of 0.58%.
Tropicana: House edge of 0.37%.
Russia: The player has a 0.2% edge, assuming early surrender against an ace is allowed.

Side Bet

There is also a Super Match side bet based on the player's initial four cards. The following table shows the pay table, probability, and return of each hand.

The lower right cell shows a house edge on the side bet of 2.55%.

Methodology

Normally I do all my own analysis on this site. However, Blackjack Switch is a very difficult game and in this case I am relying mostly on the work of a college professor in England who wishes only to be known by his initials of GM. I would like to thank GM for his contributions on this game.

Links

German translation of this article.

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