The Blackjack Rule of 23: Theory and Practice

Thousands and thousands of people play blackjack every day. Unfortunately for them, a severe and large percentage of them make critical mistakes in several types of scenarios that lower their overall payout rate and that increase the effective house advantage. Lower chances of winning both short-term and long-term are the results of these types of mistakes. Still, the blackjack rule of 23 is the type of concept that can help to prevent this sort of thing by guiding you in difficult scenarios where it’s easy to make serious strategic errors.

What the Blackjack Rule of 23 Tells Us

One of the most difficult situations to play in most blackjack games is when you have a soft total that you could either hit or double with, and both options seem promising. The idea here is that you can’t go bust by doubling, so the value of it drastically increases. However, you could catch a large card that ends up giving you a smaller total, and that could put you in a spot where you may be prone to losing to a higher dealer total. Picking between these two options can be made much simpler by using the blackjack rule of 23.

The rule of 23 says the following: When facing a weak dealer card (i.e., when the dealer has a or ), you should double if your total plus twice the value of the dealer’s card is 23 or higher.

That can seem a little complicated the first time you read it, so here’s a simple example. Suppose you have a soft , and the dealer is showing a . You would add + + to get a total of 23, which means you should double in this situation if you have the option. However, if you had a instead, then the total would be + + , which comes in at 22, and that’s a scenario where you should hit instead of doubling since you don’t quite have 23.

Other Caveats to This Rule

You’ll note that this rule only applies to games where you can double with any total, and it will also require that you’re facing a dealer who is showing a card that’s 6 or lower. It would be best if you were not doubling soft hands in most standard blackjack games when facing a 7 or higher, and doing so will put you at a tremendous disadvantage.

Moreover, this rule doesn’t apply if you have a total of 19, 20 or 21. In these scenarios, you should generally stand because your total is so strong that you already have an edge against the house.

The Importance of These Types of Guidelines

One of the biggest misconceptions that people have about strategy in blackjack is that it’s all about memorizing a chart of when to double, split, surrender, etc. (check our gambling dictionary if you are unsure about the terminology used here) Most people don’t have the time or inclination to do this. Still, something else you have to understand is that the chart would change from game to game. Unless you want to memorize a different chart for each game out there, you’ll need to learn general rules and guidelines. Like the blackjack rule of 23 that will help you to play well in a wide variety of different types of blackjack games.