How to Play Online Blackjack

March 7th, 2025

It’s great to have a blackjack strategy card to tell you exactly what to do when you are playing blackjack. However, it is always preferable to know the reason why the strategy card tells you to do something.

Sometimes it is obvious what you need to do in a certain situation. No matter how much you bet, you always need to double down or split in certain situations. This may backfire once in a while and cost you with a larger bet, but you will be losing money in the long run if you don’t. This is why it is important to know how to play blackjack.

For example, the dealer is showing a 6 and you have soft 19 (ace/8); did you know that you are always supposed to double down in this situation if you are allowed to? First, the dealer has a 42% chance of busting with a 6 showing, so even if you end up with a total of 12 there is still a good shot of winning. If you get a 10, you will still have 19 and a really good shot of winning twice your bet and there is always the chance that you will get an ace or 2 to improve your hand.

Classic Dos and Don’ts in Blackjack

Don’t ever split 10’s or 5’s
Don’t hit 16 unless the dealer has a 7 or higher
Don’t split 2’s through 7’s if the dealer has an 8 or higher
Don’t split 9’s when the dealer is showing a 7, 10 or Ace

Do split or double down every good chance when the dealer is showing a 5 or 6
Do split 8’s with the possible exception when the dealer is showing an Ace
Do double down on 10 except when the dealer is showing a 10 or Ace

Always split Aces
Always double down on 11
Always hit 12 if the dealer is showing a 2 or 3

Blackjack Odds

Of course what the section above states has to do with the percentages in blackjack and how the odds can favor the player at times. The most important blackjack odds that you need to know is the chance that the dealer has of busting. This is based off of the overall odds of receiving a certain number that won’t add up to between 17 and 21.

split-8s-in-blackjack Dealer shows 2 – 35% chance of busting
Dealer shows 3 – 37% chance of busting
Dealer shows 4 – 40% chance of busting
Dealer shows 5 – 42% chance of busting
Dealer shows 6 – 42% chance of busting
Dealer shows 7 – 26% chance of busting
Dealer shows 8 – 24% chance of busting
Dealer shows 9 – 23% chance of busting
Dealer shows 10 – 23% chance of busting
Dealer shows Ace – 17% chance of busting

The next group is based upon your probability of busting when you hit:

split-4s-in-blackjack Player has 12 – 31% chance of busting
Player has 13 – 39% chance of busting
Player has 14 – 56% chance of busting
Player has 15 – 58% chance of busting
Player has 16 – 62% chance of busting
Player has 17 – 69% chance of busting

Here is the probability of receiving a two card starting hand:

Blackjack – 4.8% chance
17 – 20 – 30.0% chance
12 – 16 – 38.7% chance
4 – 11 – 26.5% chance

Here is the probability of a dealer receiving a certain final total:

Blackjack / 21 points – 12.2% chance
20 points – 17.6% chance
19 points – 13.5% chance
18 points – 13.8% chance
17 points – 14.6% chance
Dealer qualifies – 71.7% chance
Dealer busts – 28.3% chance

The combination of the probabilities and chances shown above is why the blackjack strategy card looks the way it does. This does not mean that you have to follow the card at all times. If you have a 3 and the dealer is showing 13, you don’t always have to stay. Sometimes guessing correctly can put you on the right path.

When I have played at a casino, it always seems like you can get on a run, either hot or cold, because of one card that was or was not hit. This often has little effect in the online game, however, because you can’t be sure if the blackjack game shuffles after every hand.