Blackjack House Edge

by James Carter on February 19th, 2015.

House edge means the percentage of the player's bet the casino wins on average. This is worth figuring out since the size of house edge has everything to do with how likely you're to win. Educated players always find the games with the least house edge possible and therefore win the most - or at least lose the least.

For example, if house edge is 1.89%, the player loses $1.89 on average out of every $100 bet he makes. Obviously the player doesn't lose that amount on every single bet; you might win two hands and then lose six hands in a row but in the long run the loss will be about $1.89 per bet. One of the goals of Gaming the Odds is to teach you all about perfect blackjack strategy and to minimize the house edge. You can find several house edge percentages for blackjack game variations below in order to help you to find the best games.

The Amount of Decks

Firstly, what kind of an effect the amount decks has on casino's advantage? The table below displays the house edge for a standard blackjack game: blackjack pays 3:2, the dealer stands on soft 17, doubling is allowed for any two cards and splitting to four hands is allowed.

Number of Decks House Edge
Single Deck -0.03%
Two Decks +0.25%
Four Decks +0.38%
Six Decks +0.42%
Eight Decks +0.44%

Under those rules it would actually be profitable to play according to basic strategy with a single deck. It's always optimal to play according to basic strategy but in the vast majority of cases you're still going to have negative expectation.

Game and Rule Variations

Blackjack Games

Let's move on to the next table, which features other blackjack game variations and their house edges. In order to make it easier to compare these games, all the house edge percentages are for six-deck games unless otherwise stated.

Game House Edge
Atlantic City Blackjack +0.42%
Blackjack Switch +0.58%
Double Attack Blackjack * +0.61%
Double Exposure Blackjack +0.67%
European Blackjack +0.62%
Multiple Action Blackjack ** +0.42%
Pontoon Blackjack +0.45%
Spanish 21 +0.37%
Super Fun 21 +1.40%
Three Card Blackjack +2.10%
Vegas Downtown Blackjack +0.62%
Vegas Strip Blackjack +0.53%

* Played with a specific amount of decks (which isn't six).
** Multiple hands played but probability equal to standard blackjack.

The table above was made to give you some idea of which games are better to play than others. It's also important to remember that some casinos may operate with slightly different rules which either increase or decrease the house advantage of the game.

Blackjack Rule Variations

What about other rule variations, then? I'm going to list some of the more common blackjack rule variations and their house edges. The tables below consists of changes made to standard blackjack rules:

Dealer Hits Soft 17
# of Decks House Edge
Single Deck +0.15%
Two Decks +0.45%
Four Decks +0.59%
Six Decks +0.63%
Eight Decks +0.66%
Player Can Only Double 9-11
# of Decks House Edge
Single Deck +0.11%
Two Decks +0.36%
Four Decks +0.48%
Six Decks +0.52%
Eight Decks +0.54%
Player Can Only Double 10-11
# of Decks House Edge
Single Deck +0.26%
Two Decks +0.48%
Four Decks +0.58%
Six Decks +0.61%
Eight Decks +0.63%
Dealer Doubles on 17
# of Decks House Edge
Single Deck -0.03%
Two Decks +0.25%
Four Decks +0.38%
Six Decks +0.42%
Eight Decks +0.44%
Player Can Resplit Aces
# of Decks House Edge
Single Deck -0.06%
Two Decks +0.20%
Four Decks +0.32%
Six Decks +0.35%
Eight Decks +0.37%
Blackjack Pays 6:5
# of Decks House Edge
Single Deck +1.36%
Two Decks +1.62%
Four Decks +1.75%
Six Decks +1.78%
Eight Decks +1.80%

A couple of conclusions: first of all, the last section ("Blackjack Pays 6:5") shows you how unprofitable it is to play those games. Never play a game where blackjack pays 6:5.

Secondly, games where the player can resplit aces are preferable for the player. Try to find those games. It's also good for the player when the dealer doubles 17.

Blackjack Side Bets

And finally, blackjack side bets and house edges for them.

Side Bet House Edge
21+3 Blackjack +3.20%
21 Madness +23.00%
Bonus Blackjack +24.00%
Match the Dealer +3.10%
Perfect Pairs Blackjack +4.10%
Royal Match Blackjack +6.50%
Super Match Blackjack +2.60%
Super Sevens Blackjack +11.70%
Bust It Blackjack +7.00%

No, casinos didn't include the "side bet" option just to give players a better chance of winning. As you can see, side bets are good for the casino and bad for the player even if they might make the game a bit more exciting.

Favourable Blackjack Rule Variations for the Player

Here's a list of blackjack rule variations favourable for the player:

  • The less decks the better. (Games with one deck are the best.)
  • Double down on any 2 cards.
  • Blackjack pays 3:2.
  • Resplitting aces allowed.
  • Dealer stands on a 17.
  • Early/late surrender.
  • Low deck penetration (for card counters).
  • Insurance (for card counters).

Favourable Blackjack Rule Variations for the Casino

  • Side bets.
  • Double down on 10 and 11 only.
  • Dealer hits a soft 17.
  • The more decks the better.
  • Blackjack pays 6:5
  • Low deck penetration (against card counters).
  • No doubling down after splitting.
  • Not allowed to resplit aces.

I suggest trying to memorize these lists and look for games with beneficial blackjack rule variations for the player. Rule variations in favor of the casino should obviously be avoided.

Blackjack House Edge: FAQ

Do bet sizes impact house edge in blackjack?

It makes no difference whether you bet $10 or $10,000 - the house advantage stays the same. The amount you lose or win per bet changes, of course, depending on how big of an edge either you or the casino's got.

Which blackjack game has the smallest casino edge?

Suggesting all games are played with six decks - which is a common size for a blackjack shoe - Spanish 21 has the best house edge for the player according to the blackjack house edge table on top of this page. Standard 21 Blackjack is good too since you can actually have the edge by playing perfect basic strategy with a single deck.

How big is the house edge if I count cards?

This depends on many variables, such as which blackjack card counting systems you're going to use. In case you're using a highly complicated system, play perfectly and manage to find a good game to play, you may have a significant edge (even 3% or 4%).

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