When to Double in Single-Deck Blackjack

November 2, 2012


A number of online casinos have been offering single-deck blackjack games in recent years. People who are familiar with correct strategy when it comes to multi-deck games are often surprised that the correct strategies in single-deck blackjack are often a bit different. One of the things that changes the most when the game is dropped to using a single deck is how often you should double. Because you should double so much more often in single-deck blackjack than multi-deck blackjack, and because doubling is such an important part of the correct strategy in this game, we're going to show you when you should be doubling in this game.

In most single-deck blackjack games, you'll have the option to double with any hand total. While you can normally only double with a total of nine, ten or eleven, it's correct to double with a total of eight if you are facing a Five or Six. The only exception to this rule is that if your eight is made with a pair of Fours, then you should split instead. Totals of nine should double against all cards Six or lower, while totals of ten should double against all cards Nine or lower. With a total of 11, you should always double in single-deck blackjack. Note that doubling with 11 against an Ace isn't normally correct in multi-deck blackjack, and this is an important difference between the games.

If you have a soft total of 18 or lower, then you should always double against a Four, Five or Six. This simple rule covers the vast majority of cases for when you should double with soft totals in single-deck blackjack. You should also double against a Two or Three if you have a total of 17, and you should double against a Three if you have a total of 18. One thing that's very surprising to most people who are familiar with multi-deck blackjack is that it's correct to double in single-deck blackjack if you have a soft total of 19 against a Six.

The differences between single-deck blackjack and multi-deck blackjack are very minimal in terms of how the interface works and how the game mechanics work. However, because you're dealing with a fresh deal of a 52-card deck on every turn, the correct strategy is much different in a lot of ways. Learning when to double in single-deck blackjack is one of the keys to learning how to play this version of the game.