Understanding Blackjack Bust Percentages

Making decisions when playing Blackjack can often be difficult for a new player learning the game. You are dealt two cards but you can only see one of the dealer’s cards. You don’t know what the dealer’s second card will be and you don’t know what cards are going to be dealt. Yet you are forced to make a decision based on this incomplete information. So how do you know what is the correct decision if you don’t have all of the information you need?

You may already know about how to apply “basic strategy” to your play at the Blackjack table. This strategy tells us the optimal play in every Blackjack


situation, so we know when to hit, stand, double down or even split. You may know about basic strategy to make correct decisions but do you really understand why those decisions are actually correct?

Basic strategy has been developed using the pure mathematics of the game, tested through millions of computer simulations, based on the player’s cards and the “up card” shown by the dealer. The dealer’s up card is very important as the dealer will mathematically bust more often with certain card than with others.

For example if the dealer is showing a 5 or 6, they are going to bust 42% of the time. This is quite high so it’s common sense that your play should ensure that you don’t bust yourself and allow the dealer the chance to try and make a hand. It’s also a good opportunity to double your bet. If you hold a 10 or 11, then any ten on your next card is going to give you an excellent hand. This will happen around 30% of the time. So when you combine this opportunity with the knowledge that even if you don’t hit a ten, the dealer is a good chance to bust anyway, it’s a great opportunity to maximize your bet while the odds are in your favor.

Conversely, if the dealer shows a Ten (23% chance to bust) or an Ace (17% chance to bust) then you know that the dealer has a very strong chance of making a good hand, so you’ll need to take a risk and hit that extra card to try and make a strong hand of your own. This means that, as hard as it might be, you’ve just got to hit that not-so-sweet 16!

The chance of dealer busting based on their up card is as follows:

Dealer’s Up Card = 2 – 35% chance of busting

Dealer’s Up Card = 3 – 37% chance of busting

Dealer’s Up Card = 4 – 40% chance of busting

Dealer’s Up Card = 5 – 42% chance of busting

Dealer’s Up Card = 6 – 42% chance of busting

Dealer’s Up Card = 7 – 26% chance of busting

Dealer’s Up Card = 8 – 24% chance of busting

Dealer’s Up Card = 9 – 23% chance of busting

Dealer’s Up Card = 10 – 23% chance of busting

Dealer’s Up Card = A – 17% chance of busting

Using basic strategy in Blackjack reduces the house edge to the minimum, which can be as low as half of a percent, making it one of the lowest house edge games in the casino. By having an understanding of why you are making certain decisions, it will help your knowledge of the game and ensure that you don’t make any mistakes at the table.