Last Update: May 06, 2011
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 good comes without a trade-off. In this case a dealer 22 results in a push against all non-busted hands and blackjacks pay even money.
Russian Rules: Same as the rules above, except early surrender allowed (sometimes not against an ace), dealer does not take a hole card, and dealer stands on soft 17.
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 have not created a strategy for the Russian rules or Ontario rules.
Simple Switching Strategy
The following is the "Cindy Liu Simple Switching Strategy," appropriate under the Las Vegas rules. It is based on the following list of hands in order of strength:
Following is how to use it.
The simple strategy, compared to optimal strategy, results in a cost of errors of 0.17%. It results in an error once every 18.6 hands, and an error with an expected value of more than 10% once every 82 hands.
Advanced Switching Strategy
The following is the "Cindy Liu Advanced Switching Strategy," appropriate under the Las Vegas rules. To use it, add up the points for each hand for both ways to play them, and play the one with the greater number of points. In the case of a tie, use the the simple strategy.
Let's look at an example. Suppose you have 8+4 and A+8 against a dealer 6, where the underlined card is the second one dealt. So you can play (1) 12 and soft 19, or (2) 8-8 and soft 15. Which pair of hands is better? According to the table, the 12 is worth 0 points and the soft 19 is worth 1, for a total of 1. For the alternative, 8-8 is worth 1 and the soft 15 is worth 1, also for a total of 2. So the odds favor switching to 8-8 and soft 15. Note that the simple strategy would incorrectly advise the player to not switch. My Blackjack Switch appendix 1 shows that the combined expected value of 12 + soft 19 is -0.2108+0.3634=0.1526, and 8-8 + soft 15 is higher at 0.1461+0.0365=0.1824.
The cost of mistakes in the advanced strategy, compared to optimal strategy, is 0.08% only. The player will make an incorrect decision once every 24.5 hands, and a mistake with an expected value over 10% once every 250 hands.
I also have a printer friendly version (PDF) of both switching strategies, as well as the basic strategy.
Arnold Snyder Switching Strategy
The Big Book of Blackjack by Arnold Synder contains an easy and intuitive switching strategy. Out of respect for copyright, I won't say more than that about how it works. According to Cindy Liu, the Sndyer strategy results in a cost of errors of about 0.2% compared to optimal strategy. Besides that, I highly recommend the book for breaking new ground in blackjack, which is not easy to do any more.
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.
Under the standard Las Vegas rules, with six decks, the dealer hits a soft 17, and a switched blackjack counts as 21 points, the house edge is 0.58%, assuming optimal strategy. Follow are the effects on the house edge of some rule variations:
The house edge under the Russian rules is 0.20%, assuming early surrender against an ace is allowed.
There is also a Super Match side bet based on the player's initial four cards. The following table shows the paytable, probability, and return of each hand:
The lower right cell shows a house edge on the side bet of 2.55%.
Other Switch Pages
My thanks to Cindy Liu for both her simple and advanced switching strategies, Jing Ding for his switching calculator, and to Gabor for his mathematical contributions.