Blackjack basic strategy guide with OJO

Blackjack basic strategy is the ultimate playbook for perfect blackjack. In my guide to basic strategy, you’ll learn everything you need to play better blackjack, have more fun and keep the house edge as low as possible.

You don’t need to be a math whizz or practice for years to see the benefits of blackjack basic strategy. The expert knowledge contained in these charts and simple rules of thumbs is easy to learn and will instantly improve your play.

What is basic blackjack strategy and why does it matter?

Basic strategy is your roadmap to playing flawless blackjack. Although it’s called ‘basic’, it is actually the ultimate blackjack guide to every decision you’ll face at the table, from the first to the last.

Make no mistake, basic strategy won’t help you beat the game by gaining an edge over the house. The purpose of blackjack basic strategy is to lose the least amount of money in the long run.

When you play blackjack online, following basic strategy will ensure you are paid out the advertised ‘optimal Return To Player’. This means your bankroll will last longer and you get more bang for your buck.

The purpose of blackjack basic strategy is to lose the least amount of money in the long run.

If a game of European Blackjack has an RTP of 99.29%, that’s based on the assumption that you’ll make the best move every time you play.

Even the most experienced blackjack players may slip up in less common situations where it’s hard to choose between two options. Learning the chart or keeping a copy to hand is the only way to ensure you’re not giving the house more than they deserve!

Strategic errors can turn blackjack from a casino game with the highest RTP to one with the lowest. As you can see from this table, knowing when to hit or stand is the most important decision in blackjack, while doubling and splitting also have a small but significant impact.

Action

House edge if used incorrectly

Stand or hit

-3.50%

Double

-1.60%

Split

-0.40%

Imagine you’re the worst blackjack player ever! You go for the wrong move every time, and the game now has a house edge of over 5%! Here’s how it works in practice.

Players A and B play 200 hands at £5 per hand at the same table. One follows basic strategy and the other makes the worst possible decisions. Thanks to his mistakes, Player B loses 13 times more money than he would have done if he had followed basic strategy. It pays to know your basic strategy!

Basic strategy charts and how to use them

It’s no good calculating the optimal move for more than 9 billion combinations of player and dealer cards if you can’t check them at a glance.

Enter the basic blackjack strategy chart, a simple graphic that contains all of blackjack’s secrets.

Once you know your starting hand and the dealer’s up card, a basic strategy chart lets you quickly find out the recommended move that will produce the best outcome in the long run.

Because of the luck element in blackjack, it’s still possible to lose any individual hand (even from a winning position). But you can be certain that you took the right mathematical decision that maximized your profit or minimized your loss in that specific situation.

Blackjack basic strategy chart for 4-8 deck game where dealers stands on Soft 17

Because blackjack rules can be different from one table to the next, it’s important to pick the right basic strategy chart for the game you’re playing.

The advice in each chart can be different depending on how many decks of cards are used, whether the dealer stands or hits on Soft 17, when doubling is allowed and so on.

Although all basic strategy charts look very similar, there are small variations in strategy.

Take 11 against a dealer’s Ace, for example. In a multi-deck game where the dealer stands on Soft 17, you should hit.

At a table where the dealer hits on Soft 17, it’s better to double. In all single-deck games, you should double down.

As there are many variations of blackjack rules and we can’t cover them all when discussing specific scenarios. The remaining advice in this guide relates to the most popular set of blackjack rules played in the UK, an 8-deck game where the dealer stands on Soft 17.

If you play games in the USA, the best plays and percentages I give may be slightly different, and you should always refer to the correct chart.

Surrender rules in basic strategy

when to surrender at blackjack

In some situations, your chances of winning are so small that it’s better to forfeit your hand, get half your money back and move onto the next battle.

If used correctly, the surrender rule can be worth up to 0.60% in terms of house edge.

You should only surrender if your chance of winning a hand is 25% of lower.

There are only a handful of blackjack scenarios where this happens:

  • Surrender 16 against 9, 10 or Ace. Hitting is the standard play and results in a 57p loss for every £1 you stake. If you surrender, you lose 50p instead.
  • Surrender 15 against 10 or Ace. Against an Ace, you lose 64p on average, so surrendering 50p is clearly the better play.

Basic strategy advice on splitting pairs

blackjack table with a split pair of Eights and a stack of chips

Of all the decisions you’ll take at the table, splitting pairs is the least important, but doing it wrong will still cost you a small edge in the long run.

There are 2 reasons to split a pair. Either you’re getting more money in play against a weak dealer hand, or your cards work better alone than they do together.

In basic strategy, splitting can be summed up with these 3 rules:

  • Never split Tens. We turn 1 hand worth 20 that wins most of the time into 2 hands that are likely to end up being worse.
  • Always split Aces except against an Ace. You might only get 1 card but Aces are worth 11, the magic number!
  • Split any pair except Tens and Fives against a weaker dealer card. This is a broad rule of thumb and there are exceptions.

Basic strategy rules for doubling down

when to double down while playing blackjack

In a game where you’ll win the hand only 42% of the time, you need a secret weapon to balance the scales. Winning 3 to 2 for Blackjack is by far the most important advantage you’ll get, but doubling correctly is a powerful tool as well.

Doubling is as much about capitalising on dealer weakness as it is your own card strength. Of the 48 squares in a basic strategy chart which advise you to double, 38 occur when the dealer has 6 or less.

  • Double on 9, 10 or 11 when the dealer’s up card is the same or lower than yours.
  • Avoid doubling on 11 against 10 or Ace. It’s still (very marginally) profitable but hitting is a more profitable play.
  • Double on all Soft hands worth 18 or less against 5 and 6. Doubling Soft hands which include an Ace is one of the secrets of winning blackjack. There are exceptions to this rule in basic strategy charts but in general, this will serve you well.

Hitting and standing in blackjack: The bread & butter of basic strategy

when to hit or stand at blackjack

If you can’t surrender, split or double, you’re left with 2 options, hit or stand. This is the most common situation you’ll find yourself in, which means blackjack basic strategy rules for hitting and standing are the most important rules to learn.

When to hit in blackjack

While there are various reasons to stand, double or split, there is only 1 reason to hit and take another card in blackjack. Your hand isn’t good enough yet!

Left as it is, your hand won’t beat the dealer’s often enough to be profitable, so you need to improve your score.

If your hand is worth 11 or less, you can hit without fear of busting. With 12 or more, it’s a different story. A lot of blackjack players fear busting and stand instead of hit, choosing to take their chances with a weak hand, probably as they’ve seen it win.

But the numbers are the only thing that matter in blackjack, and it’s often necessary to try and improve your hand, even when your risk of busting is high.

When you hit on 16, you’ll bust 62% of the time. But if the dealer has 7 or more, they’ll make 17 or more so often that you must take that risk.

  • Hit on 8 or less. You cannot bust yet, so there’s nothing to be scared of. If you have 9, 10 or 11, the same is true but doubling down often becomes the most profitable play.
  • Hit 9, 10 or 11 against an Ace or 10. You can’t busy yet and doubling is too aggressive.
  • Hit on 13 to 16 against a 7 or more. The dealer will make a pat hand over 60% of the time so your hand won’t be enough as it stands.
  • Hit on 12 against a 2. You might not expect to hit with 12 against low dealer cards, but 12 is a special case. There’s an old blackjack saying that “2 is a dealer’s Ace”, as it enables them to make a pat hands so often (about 2 out of 3 times).
  • Hit Soft 18 or less against 9, 10 or Ace. With the safety net of not being able to bust, it’s usually correct to hit and try to improve your hand.
  • Hit all pairs from Sevens down against a dealer’s 8 or more. Better to take your chances rather than creating 2 new weak hands.

When to stand

When basic strategy says to stand, it’s usually because your hand is in good shape, or your hand is bad but so is the dealer’s!

In all cases, sticking with what you’ve got is better than risking going bust.

To illustrate why it’s often so important to stand and rely on the dealer busting, here are the bust rates for all dealer up cards.

As you can see, against 4, 5 or 6, you’ll win automatically over 40% of the time, whatever cards you’ve got.

Dealer up cards and how often they will bust

2

3

4

5

6

7

8

9

10

11

35%

36%

40%

42%

42%

26%

24%

23%

21%

12%

Standing rules

  • Stand on Hard 17 or more against any card. Your hand is in good shape against most dealer cards, plus it would suicidal to hit!
  • Stand on Hard 12 to 16 against 2 to 6. The dealer will bust between 32-45% of the time, so we shouldn’t risk busting ourselves. There is an exception when you have 12, when standing is not the right play. This is due to a combination of lower dealer bust rate and your own improved rate of making a better hand.
  • Stand on Soft 19 and Soft 20. You’re in good shape against any dealer card, and your hand is too strong to risk making it worse by doubling down. The exception is Soft 19 against a 6, when you should double instead. The dealer’s hand is just too bad to pass up the chance to double down.
  • Stand on Soft 18 against at 7 or 8. With soft 18 you should double, stand or hit depending on the situation. Standing against a 7 or 8 is the logical play.

How insurance works in basic strategy

how blackjack insurance works

Insurance and its closely-related cousin Even Money are side bets the dealer will offer you in specific situations.

If the dealer shows an Ace, you might be offered blackjack insurance. If you have Blackjack and the dealer shows as Ace, you’ll be offered Even Money instead.

Both share similar qualities; They’re side bets that sound like a good deal for the player, but are actually good news for the house.

Although it may work out for you on any individual hand, the truth is that any time you take either insurance or even money, you play a new game with a much higher house edge.

When you take insurance, you’re playing a new game with a much higher house edge. The general rule is never to take insurance at all.

You won’t find either insurance or even money in most blackjack basic strategy charts because they’re not blackjack!

They may be offered at the table, but they are side bets and the correct strategy is stunningly simple – say no to both! Here’s why…

How insurance works

Blackjack insurance sounds like a way to protect a good hand, and in some ways it is.

This is a 2 to 1 bet (for half the stake of your main hand) that the dealer makes Blackjack with a 10 as their second card.

By placing this extra bet and winning, you cover the possible loss of your main hand, although you can still lose both the Insurance bet and the main hand (if the dealer does not make Blackjack, but goes on to make a better hand than yours), so beware!

The best way to look at blackjack insurance is to see it for what it is – a very simple side bet that the dealer’s second card will be worth 10.

The 2 to 1 payout you’re offered is slightly worse than the true odds of the dealer drawing a 10, which is where the 7% house edge comes from.

As a result, the insurance side bet has a much worse return to player than blackjack itself. Unless you’re counting cards and can spot when the deck is rich in Tens, insurance is not a good bet.

Even Money explained

Even money is a lot like insurance except that instead of saving money, the benefit here is the prospect of a guaranteed win.

Even money is the blackjack side bet equivalent of the old saying ‘a bird in the hand is worth 2 in the bush’. Except mathematically it’s not better at all.

Let’s say you make Blackjack, but the dealer shows an Ace. Many players would happily give up the chance of a 3 to 2 payout if they are offered an instant, no-risk 1 to 1 payout. A guaranteed win sounds good, but the maths are bad.

The dealer will only make his own Blackjack around 30% of the time. The other 70% of the time, you win 3 to 2. By taking evens in this scenario, you give up 4% of your winnings in the long run.

The history of basic strategy

Although some variation of blackjack has been played since the 18th century, it wasn’t until the 1950’s that the first theories around basic strategy first appeared, starting with Roger Baldwin’s book ‘Playing Blackjack to Win: A New Strategy for the Game of 21’.

By the 1960’s, academics at MIT and IBM had become interested in applying their new computing power to blackjack.

Their technology could simulate millions of hands of blackjack and produce a figure for average profit or loss for every possible combination of player and dealer cards.

By comparing the outcomes of different decisions in the same situations, they could prove which moves were most profitable (or least unprofitable).

The father of card counting, Edward Thorp, used high speed computers to advance his own blackjack strategy but it was the work of IBM scientist Julian Braun and Peter Griffin, whose computer modelled over 9 billion gameplay scenarios, that produced the chart we now recognise as Blackjack basic strategy.

More refined versions have been computed but this 60-year-old chart is still the ultimate tool for perfect blackjack.

How much to bet when you use basic strategy

What to bet

Basic strategy in blackjack is all about the best decisions once everyone’s got their cards. The charts won’t tell you how much to bet, or if you should change your bet size from hand to hand.

You now know the optimal plays in blackjack but it’s worth taking a moment to look at the pros and cons of the most popular betting strategies.

Basic strategy is about reducing the house edge, while betting strategy is about managing risk.

There are 3 factors that matter most when determining your approach to bet size, your bankroll, your goal and your recent run of results.

Bankroll

Your blackjack bankroll is the total amount of money you are willing to spend in a session (or it could be a proportion of your overall gambling bankroll for the year).

For the purposes of safer gambling, make it entirely separate from your life expenses and an amount you are prepared to lose.

That lets you play blackjack without fear and always follow the right basic strategy play. There’s no point knowing you should split a pair against an Ace if you haven’t got the chips to back it up.

There’s also no point in betting 20% of your stack, as you will bust your stack more quickly. This type of bankroll strategy increases the so-called ‘risk of ruin’, or the likelihood of losing all of your bankroll too early.

In blackjack, betting 5% or even 1% of your chips on each hand is a safer bet.

Goals

Players have a wide range of different goals when they join a blackjack table. Some are happy to just be there. They see the money they spend as the price of an hour or two of entertainment.

Some have a number in their head (“I’ll play with £50 and if I get to £150, I’ll take the profit”). Whatever outcome you’re looking for, the pattern of results in blackjack can be harnessed to fit most sensible goals.

Results

Your recent run of results is important. If you’ve been playing for an hour, you’ll either be up, down or roughly where you started, depending on short term fluctuations in luck.

If you’re up or down 20 bets for example, you can choose whether to stick with your original bet size, reduce it or increase it. This depends on your goal for the session, how long you think you’ll continue to play and your attitude to risk.

The most common betting strategies

Choosing how much money to bring to the table and what percentage of it to bet on any hand are the same decisions investors make when they buy shares. Some investors are conservative, some are aggressive. Blackjack players are the same and each has their own risk profile and betting approach to match.

Flat betting

In this option, you bet the same amount on every hand, whether you’re up or down.

It’s the simplest strategy to follow – no thinking required! – and a more conservative method of managing your chips. 

As long as you play perfect strategy and only ever bet a small proportion of your stack, your bankroll should see you through even the longest of sessions.

The downside of this investment strategy is that while it is low risk, it is also low reward.

You won’t bust your stack quickly, but it would take an incredible run of wins to come away with a big profit.

Random

This might seem a strange approach but it’s more common than you think, especially in land-based casinos where players reach down and grab a chunk of chips from the top of their stack.

Going by feel, hunch, superstition or genuine randomness can keep you interested and keep the dealer on her toes. Although it’s more difficult to track how many hands you’ve won or lost, it is not the worst type of blackjack betting strategy I’ve seen!

Increase when you win

This is the pro’s take on blackjack betting, and indeed many gambling games, if they’re looking to book a big win using the house’s money.

I call it an asymmetric’ model because it minimizes your downside but maximizes your upside.

It was designed to produce the occasional big winning session although it is balanced out by many more small losing sessions.

This strategy usually involves cutting your stake when you’re on a losing run, and it’s this defend-when-you’re down, push-when-you’re-up approach that many professional blackjack players and gamblers favour.

Increase when you lose

This is OJO’s biggest no-no. Increasing your bet if you’re down is called chasing losses.

There are many reasons why it’s a terrible strategy, not least because you’ll always end up exceeding the table’s maximum bet and you won’t be able to continue.

The most famous version of this strategy is called Martingale Strategy, where you double your bet every time you lose.

There is virtually no upside to this approach, but on the downside, you almost always end up making very large bets which can only get you back to break even, or book a small profit.

If players do get out of the hole by ending a string of losing hand with a win, they usually reduce their stake back to the original amount.

This means you can lose big, but only ever win small. Not good!

Are you ready to play blackjack?

Basic strategy is not only the most important part of learning how to play blackjack, but as you can see from the sheer volume of information we’ve covered, it’s the most detailed aspect of blackjack play too.

Don’t worry if you’ve already forgotten some of the advice. No one ever learned basic strategy in a day!

Daniel Grant

Dan Grant has been writing about gambling for 15 years, and been fascinated by beating the odds for even longer. Now he’s on a mission to help others bet smarter and avoid the mistakes he made. When he’s not obsessing over bankroll strategy or counting cards badly, he’s hosting The OJO Show podcast.

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