Blackjack probabilities
May 17, 2007 - Gunilla Larsen
In most casino games of blackjack, the house advantage (the dealer advantage) is around 8%. The house gets this advantage because the dealer is the last player to act and all players have already made their decisions.
By using correct blackjack basic strategy, you can turn the casino edge in blackjack from 7%-8% down to 0.5%. If you correctly use advanced card counting techniques, you can often change blackjack odds and give yourself the advantage over the casino. Manipulating the house odds to your favour is the reason most casinos don't allow card counters to play blackjack.
Probability of busting
It's very important to know the probability of your hand busting when you are holding any total in the game of blackjack. The following odds chart shows the blackjack odds of busting, depending on your current hand value:
| Hand value | % bust if you hit |
| 21 | 100% |
| 20 | 92% |
| 19 | 85% |
| 18 | 77% |
| 17 | 69% |
| 16 | 62% |
| 15 | 58% |
| 14 | 56% |
| 13 | 39% |
| 12 | 31% |
| 11 or less | 0% |
Dealer final hand probabilities
This blackjack odds chart shows the dealer final hand probability. These are the percentages that the dealer will end up with a hand totalling each corresponding value (up to 16).
| Dealer final hand value | % | Cumulative % total |
| Natural 21 | 4.82% | 4.83% |
| 21 (3 or more cards) | 7.36% | 12.19% |
| 20 | 17.58% | 29.77% |
| 19 | 13.48% | 43.25% |
| 18 | 13.81% | 57.06% |
| 17 | 14.58% | 71.64% |
| 16 | 28.36% | 100.00% |
Player advantage vs. dealer up-card
The first two columns in this odds chart explain the dealer's chance of busting, depending on the up card that he is showing. The dealer has the highest chance of busting when he is showing a 5. The third column in this chart shows the player advantage of using basic strategy, compared to each up card the dealer is showing. The player has the highest advantage of 23.9%, when the dealer is showing a 5. When the dealer is showing any card that is 9 value or higher, the player is in the negative advantage range.
| Dealer up card | Dealer bust % | Player advantage % with basic strategy |
| 2 | 35.30% | 9.8% |
| 3 | 37.56% | 13.4% |
| 4 | 40.28% | 18.0% |
| 5 | 42.89% | 23.2% |
| 6 | 42.08% | 23.9% |
| 7 | 25.99% | 14.3% |
| 8 | 23.86% | 5.4% |
| 9 | 23.34% | -4.3% |
| J,Q,K | 21.43% | -16.9% |
| A | 11.65% | -16.0% |
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