The Theory Behind Blackjack on When you Hit, Stand, Split or Double Down

Understanding When to Hit, Stand, Split or Double Down in Blackjack

We can assume before choosing to play the game of online blackjack, you have already read our blackjack strategy page. Perhaps you looked at, or possibly you have printed our multideck blackjack strategy card. This article helps you understand when you will or will not hit. Should you stand, take insurance, double, split, and if available, surrender?

If you have not printed out the strategy card, you should open it in a new tab so you can refer to it for better understanding.

Splitting a Pair

The theory is simple. With slightly more than 30% of the deck being comprised of 10 value cards, there are simply some situations where you will or won’t split.

Let’s say you have a pair of 8’s. That’s 16 right? Well the dealer is going to hit until he has 17 or better so you’re sitting with a pretty poor hand. Split them though, and you may draw 2 tens to supplement the 2 hands you have and you now have a far more competitive hand.

The same of course applies to a pair of aces. It’s worth 2, 12, or bust. VERY weak. But what if you split them? You have a pretty good chance of getting two hands worth 21! You won’t however split a pair of 10 value cards. 20 is already a great hand so why mess with it.

Hitting on a pair of 5’s is great too, you have a fair chance of 20. Split them and you could end up with 15 which is difficult to hit and to stand. 15 is not a strong hand either, so try to avoid ending there. That’s quite simple isn’t it?

Doubling your Bet or To Double Down

Let’s say you have a 5 and a 6. The dealer is sitting with a 7. Go for it and double your bet, you have a good chance of drawing a winning hand. With so many 10’s, plus some nines and eights about, the poor dealer needs loads of luck to beat you. A dealer with a 6 is in a difficult position because he cannot stand on 16 (assuming he draws a ten). So, if you’re sitting with an appropriate hand, double and nail him. You can also stand if you are on a weakish hand because the dealer will have to draw 2 cards to qualify. In that situation there is a good chance of him going bust.

When to Take Insurance in 21

Taking insurance comes about when the dealer has an ace showing. It costs half your original bet and will result in your original bet being refunded if the dealer has a blackjack. Although there is a decent chance that he will draw a 10 card, the odds are not that good that they make up for the addition 50% bet outlay. In the long run it won’t pay to take insurance. This doesn’t strictly apply in a land based casinos. Professional card players who are counting the cards can improve their estimation of the chances that the dealer has blackjack and insurance could be viable in some cases.

Hitting and Standing in Blackjack

As alluded to above, the dealer must hit until he has 17 or better. This means that you get to guess his next card (and 10’s make up a great proportion of the deck). A dealer with a 5 is terribly weak because he will definitely have to draw 2 cards. Even if you have a relatively weak hand it will pay to stand and watch him bust in most cases. A dealer with a 9 showing stands a good chance of getting 19 so if you’re on 16 you’re going to need to hit. It’s all simple though, the calculator works out the odds and you simply play according to them.


In some casinos the game gives you the option to surrender for a percentage value of your bet. If the odds are stacked against you, then surrender can be an option. Again the odds are calculated and the decision to surrender is take in light of the predicted outcome of the hand.

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