Blackjack Rules and Their Effect on the Odds
Everyone thinks they have a good grasp of blackjack rules, but some people don’t realize that blackjack rules can change from table to table and from casino to casino.
And the effect that the rules have on your odds of winning can be dramatic.
You measure the advantage that the casino has over the player with a metric called “the house edge.” That’s a percentage of each bet that the casino expects to win in the long run given the rules and payouts for a casino game.
If the house edge is 1%, the casino expects you to lose an average of $1 per $100 you bet. If it’s 0.5%, the casino only expects you to lose an average of 50 cents per $100 you bet.
This sounds like a small amount, and it is, but when it comes to blackjack, the rules changes can dramatically affect the numbers you’re dealing with.
The biggest factor in blackjack, of course, is whether you use appropriate basic strategy. That’s the mathematically correct way to play every hand. If you ignore that and just play with your gut, you’re probably giving 2% back to the casino on top of the house edge.
But besides that, you need to be able to scout out the best rules to get the best house edge.
This post begins with the basics of blackjack, then I look at the biggest changes in the rules from table to table and casino to casino, along with their effect on the house edge.
Always try to find blackjack game with the lowest house edge, and always use basic strategy to try get the house’s edge as low as possible.
The Basic Rules for How to Play Blackjack
You might already know the basics, but here they are again. You must have mastered these before you can play, anyway.
Blackjack is played at a casino table. Each player competes with the dealer, not each other. The game starts when each player has placed his bet.
The dealer gives each player 2 cards, while dealing himself 2 cards, too. In a game with a single deck, the players’ cards are dealt face down. With multiple decks, you get your cards face-up. The dealer’s cards include a face-up card and a face-down card.
After you look at your cards and the dealer’s face-up card, you get to decide what to do with your hand.
Blackjack is a comparing game based on a points system. A hand is worth the total of the points in it. Each card is worth the following number of points:
- Aces are worth 1 or 11 points.
- 2, 3, 4, 5, 6 7, 8, and 9 are worth that many points, respectively.
- 10s are worth 10 points.
- Jacks, queens, and kings (face cards) are also worth 10 points.
A 2-card hand worth 21 points is a “natural” or a “blackjack” and is an automatic winner for the player as long as the dealer doesn’t also have a blackjack.
The only way to get a blackjack is to get an ace and a card worth 10 to accompany it.
A blackjack almost always gets a higher than even money payout.
If you have any total lower than 21, you can take more cards or stand. If you take more cards and end up with a total of 22 or more, you’re said to have bust, which means you automatically lose – even if the dealer busts his hand when he plays it.
That’s the main reason the house has an edge in blackjack, in fact – the dealer acts last.
The dealer has certain rules he must follow regardless of what you’ve done or what cards you’re holding. For example, the dealer always must hit a total of 16 or less, even though you have the option of standing on such a total.
If your total ties the dealer’s total, the hand results in a push, which means you get your bet back with no winnings.
If the dealer busts, or if you have a final total higher than his, you win even money on your hand.
If the dealer has a higher total, or if you bust, you lose your bet.
How Much Does a Natural Pay?
I mentioned that a natural or a blackjack has a bonus payout. In other words, winning hands pay even money, but a blackjack pays off at better than even money. A 3 to 2 payout for a blackjack is typical.
But you can find casinos sometimes offering bonuses like a 2 for 1 payout for a blackjack, which reduces the house edge dramatically.
You can also find a lot of games where the casino pays out 6 to 5 on blackjack. Some of them even act like this is some kind of bonus for the player because 6 is bigger than 3. It’s actually became a common practice in Vegas casinos to offer single deck blackjack with 6/5 payouts to “mislead” the players.
If you can find a casino that pays 2 to 1 for a blackjack, that reduces the house edge by 2.27%. This is usually enough of a difference to make a negative expectation game into a positive expectation game for a player.
If a casino is offering a 6 to 5 payout for a blackjack, that increases the house edge by 1.39%, which is a tremendous boon for the casino.
If you can find a game that offers 2 to 1 for a blackjack, you should always play it.
If you’re facing a game with a 6 to 5 payout for a blackjack, you should never play it.
What Totals Can You Double Down On?
One of the options that you have besides just taking another card is doubling down.
When you double down, you agree to increase the size of your bet to double what it was originally. (In other words, if you bet $10, you would have to put up another $10 to double down.)
When you double down you get one more card and your turn ends. No matter what the next card is, you don’t get to take another card.
Many casinos limit you to only being able to double down on certain totals.
For example, you might be playing in a casino where you can only double down on a total of 10 or 11.
Some casinos might have a range of 9, 10, or 11, while others might allow you to double down on any 2 cards.
It’s probably obvious, but the more flexibility you have, the better the game is for you.
In a game where you can only double down on 10 or 11, the house edge increases by 0.18%.
If you can double down only on 9, 10, or 11, the house edge increases by 0.09%.
The goal when doubling down is to get more money into action when you’re more likely to win. For example, if you have a total of 11, your next card cannot possibly bust your hand.
There are more 10s in the deck than any other point-total, too, so you’ll hit a total of 21 –the best possible total – a higher percentage of the time.
Always try to find games where you can double down on any total, regardless of the situation. (I’ll have a little more to say about doubling down in the section on splitting aces.)
How Many Decks Are in Use?
The more decks the casino is using, the worse the odds are for the player. The best possible game – everything else being equal – is a game dealt from a single deck.
In fact, most of the time, when you’re playing at a casino online, the single deck has the best odds at the casino – sometimes less than 0.3% if you use perfect basic strategy.
A single deck game takes 0.48% away from the casino’s edge, so that’s a big margin – not as big as the differences in payouts, but big nonetheless.
A double deck game is almost as good – it gives the player 0.19% back.
Even 4 decks is borderline reasonable, giving 0.04% back to the player.
The worst possible blackjack game you can play is one dealt from 8 decks that are constantly being shuffled. These prevent you from counting cards (which isn’t an issue with an online casino, anyway), but even an 8 deck game where the cards get shuffled periodically are better than a game where the cards are shuffled constantly.
For that reason, in most online blackjack sites the game that is simply called blackjack (or classic blackjack) will be played with 8 decks. They know that most players will avoid unfamiliar names and will play this game and this is one of the biggest mistakes you can do in blackjack.
What Are the Rules for Surrendering?
Surrendering in blackjack is similar to folding in a game of Texas holdem. You give up any chance of winning the hand, BUT you do get half your original bet back.
You have 2 possible rules related to surrendering – early surrender or late surrender.
Early surrender is, of course, better for the player.
Early surrender gives you back 0.24% or 0.39%, depending on whether you’re able to make this move facing a 10 or an ace. Early surrender means you get to surrender BEFORE the dealer checks his hole (face-down) card.
Most casinos don’t offer early surrender, and it’s not a tactic you’ll use often, anyway.
Late surrender is more of a break-even proposition.
What Are the Rules for Splitting Aces?
When you get dealt a pair of cards – 2 cards of the same rank – you have the option of splitting those cards into 2 new hands. The 2 cards that were in your hand previously become the starting hand cards for 2 new hands, and you get a new card added to each of those hands.
Of course, to split these cards, you need to put up a 2nd bet – one for the new hand, and you already have one up there for your original hand. (here you can find article with focused on all splitting options in blackjack).
But what happens when you get 2 aces?
The correct move is always to split aces, but some casinos will allow you to re-split aces if you get a pair of aces again. This is, obviously, better for the player.
Some casinos will also allow you to double down on a hand that includes an ace after splitting, but most don’t.
If you’re allowed to re-split aces, the house edge drops by 0.19%.
If you can double down after splitting aces, that gives you another 0.15% off the house edge.
Are There Bonus Payouts for Hands with a Certain Number of Cards?
One of my favorite rules is the 5-card Charlie rule.
This is a rule where you get a bigger payout for a hand with more cards in it that doesn’t bust.
This is a GREAT rule for the player – it reduces the house edge by 1.46%.
Some casinos also give bonus payouts if you have 5 cards or more and beat the dealer, treating it like a blackjack and giving you a 3 to 2 payout. This reduces the house edge by 0.33%.
Does the Dealer Hit a Soft 17 or Stand?
If the dealer hits a soft 17, it hurts your odds by 0.22%. Most casinos do require their dealers to hit a soft 17.
A “soft” total is one that includes an ace. It’s called a soft total because you can count the ace as a “1” instead of an “11” and avoid going bust.
If you can find a game where the dealer must stand on a soft 17, go for it instead. It’s much better for your odds.
What Are the Most Important Rules Changes to Look Out For?
- The first thing you need to do is make sure you’re not playing in a 6/5 blackjack game. You probably won’t be able to find a game that pays 2 to 1 for a blackjack, but if you do, you should always play in it.
- The next most important rule to look at is how many decks are in use. Fewer decks are always better. Find a single deck game if you can.
- The third most important rule to look for is whether the dealer hits or stands on a soft 17. Always play in the game where the dealer stands on all totals of 17.