wageringterms.

Definition

Bust

Also known as Break, Go Bust, Bust Out

By Reviewed Editorial policy

In short

To bust is to exceed 21 in blackjack, losing the hand immediately. Because the player acts first, a player bust loses even if the dealer would also have busted, which is the source of the house edge.

Busting means going over 21. The hand is lost immediately, the chips are collected, and what the dealer does afterwards is irrelevant.

This is where the house edge comes from

If both player and dealer busting were treated equally, as a push, blackjack would be close to a fair game. It is not. The player acts first, so a player bust is settled before the dealer plays.

Roughly 8% of hands feature both the player and the dealer busting. In those hands the player loses, purely because of the order of play. That asymmetry is essentially the entire structural edge in blackjack, and all the favourable rules, 3:2 blackjacks, doubling, splitting, exist to give most of it back.

Bust probabilities

Your chance of busting on a single hit:

Hand Bust chance
11 or less 0%
12 31%
13 39%
14 46%
15 54%
16 62%
17 69%
20 92%

And the dealer’s chance of busting, by upcard:

Upcard Dealer bust %
2 35%
3 37%
4 40%
5 42%
6 42%
7 26%
8 24%
9 23%
10 21%
Ace 17%

The 5 and 6 are the dealer’s worst cards, which is why basic strategy stands on so many weak hands against them.

Avoiding busts is not the goal

The common instinct is to never hit a hand that might bust. It costs money.

Standing on 16 against a dealer 10 avoids a 62% bust chance and accepts a 77% loss chance instead. Minimising busts and minimising losses are different objectives, and the chart optimises the second.

Soft hands cannot bust on a single hit, since the ace revalues from 11 to 1. This is why soft totals are always worth hitting at low values.

Common questions

What are the odds of busting in blackjack?

It depends entirely on your total. You cannot bust on 11 or less. On 12 it is 31%, on 16 it is 62%, and on 20 it is 92%. A soft hand containing an ace as 11 cannot bust on a single card.

Why do I lose when the dealer also busts?

Because you act first, so your bust is settled before the dealer plays. Roughly 8% of hands feature both busting, and the player loses all of them purely because of the order of play. That asymmetry is essentially the whole house edge.

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