Most players understand that the casino holds an advantage in blackjack. This advantage is known as the house edge, and is usually under 1% in most blackjack games, provided players play using the optimal basic strategy under the rules of the game they’re playing.
What does that house edge mean? It’s an expression of how much of each bet the house can expect to win on average over the long run. In other words, if the house edge is 1%, and you make bets of $100, you can expect the casino to win $1 for every bet you make. Obviously, no bet in blackjack would cause you to lose exactly $1 on any given $100 bet; however, if you played tens of thousands of hands, you would see that the casino was coming out ahead by about that 1% margin.
Keep in mind that the house edge is based on how much you expect to lose (or in the case of a player advantage, win) expressed as a percentage of your initial bet. This does not include additional wagers you might make during the course of play, such as splitting and doubling down. In other words, in the above example, you’ll be expected to lose $1 per hand, because $100 was your initial bet; that is where the 1% figure comes from. The results of doubling down, splits, blackjacks and everything else are figured into that calculation. It is possible to express the house edge as a percentage of the entire amount wagered during play; Michael Shackleford of “The Wizard of Odds” refers to this number as the “element of risk.”
Blackjack Rules and the House Advantage
Not surprisingly, different blackjack rules can have an impact on the size of the house edge. Some rules variations are beneficial to the player, while others increase the casino’s advantage.
The following is a rundown of how different rule changes can affect the house edge. Again, credit goes to The Wizard of Odds for their excellent analysis of how rules affect the casino’s advantage. All rule changes and their effects are rated against a typical game with the following rules: a blackjack game with an eight deck show, where the dealer stands on all 17s, the player may double on any two cards, the player can double down after splitting, and the maximum number of hands the player may split to is four. This game would have a house edge of about 0.45%.
Many promotional rules are sometimes offered which can offer a lot of help to the player. For instance, if blackjacks pay 2-1, the house edge is reduced by 2.27%. The following are some other possible promotional rules variations that help the player, along with the amount by which they reduce the house edge:
- Triple Down: -1.64%
- Five Card Charlie: -1.46%
- 2-1 on Suited Blackjacks: -0.57%
- Six Card Charlie: -0.16%
- Seven Card Charlie: -0.01%
Using Fewer Decks
Most players have heard that blackjack games with fewer decks are friendly to players, but you might be surprised to find that the differences between these games are relatively small. In fact, the player will see almost no advantage unless only one or two decks are being used. Here’s how reducing the number of decks affects the house advantage:
- Six Decks: -0.02%
- Five Decks: -0.03%
- Four Decks: -0.06%
- Two Decks: -0.19%
- One Deck: -0.48%
Changing How the Dealer Plays
One of the biggest rules variations between various casino blackjack games is whether the dealer stands on all 17s, or hits on soft 17s. The standard rule of hitting on all 17s is actually better for the player; if the dealer hits on soft 17, the house advantage is increased by 0.22%.
Changing the options available to the player can also have an impact on the house edge. Sometimes, this is beneficial; for instance, allowing early surrender – the option to surrender before the dealer checks for blackjack – can reduce the house edge by up to 0.39%. Allowing the player to continue playing their hands as normal after splitting aces reduces the house edge by 0.19%.
However, in most cases, casinos are more likely to eliminate player options rather than give the players a helping hand. Here are some rule changes that limit what the player can do, and their associated increases in the house edge.
- Players can only split to three hands: +0.01%
- Players can only split to two hands: +0.10%
- Players may double down only on 9, 10 or 11: +0.09%
- Players may not double down after splitting: +0.14%
- Players may not split aces: +0.18%
Blackjack Short Pays
Perhaps the worst rules variation that can be found at some casinos is the short pay blackjack. In almost all casinos, especially online casinos, blackjacks will pay 3-2 odds. However, some casinos offer blackjack games that offer less than this. While it may seem like a minor change, even a small reduction in the odds given for a blackjack can have a huge impact on the house edge, turning what looks like a good blackjack game into a poor one. Here’s how short paying blackjacks increase the house edge:
- Blackjack Pays 7-5: +0.45%
- Blackjack Pays 6-5: +1.39%
- Blackjack Pays 1-1: +2.27%
Casino House Advantage Infographic