Black Jack odds

In this article, we will take a look at some factor that impact the odds for blackjack. There are many rules at the blackjack table that has a significant impact on the house edge. Even a seemingly minor rule change can increase the house edge with an amount significant enough to take you from long-term winner to long-term loser at the blackjack table.

The number of decks

oddsWith all other things being equal, playing with few decks gives the player better odds than playing with many decks.

If a player gets a ten as their first card, the chance of getting an ace as the second card is higher the lower amount of decks that are in use.

Playing with fewer decks will also decrease the chance of the dealer getting a blackjack when you already have a blackjack.

When a casino offers Single Deck Blackjack or blackjack with just two decks, they tend to compensate by tightening other rules to retain a favorable edge for the house. The casino may for instance pay 6:5 instead of 3:2 on winning blackjacks, or disallow doubling on soft hands.

Comparison

Let’s assume that we are at a blackjack table where the various rules have created a situation where the house edge is 0.65 percent when blackjack is played with eight decks.

This is how the house edge would change if we decreased the number of decks, without changing any other factor.

  • If we reduce the number of decks to six, the house edge isn’t impacted much. It drops from 0.65 percent to 0.64 percent.
  • If we reduce the number of decks to four, the house edge goes down to 0.60 percent.
  • If we reduce the number of decks to two, the house edge goes down to 0.46 percent.
  • If we reduce the number of decks to one, the house edge goes down to 0.17 percent.

As you can see, changing from one deck to two decks has a much greater impact than changing from six decks to eight decks, even though the first change is a change by one deck only while the second change is a change by two decks.

Pay for winning blackjacks

At a standard black jack table, you get paid 3:2 for a winning blackjack. Changing this rule will impact the odds.

At a 6:5 Black Jack table, you are paid 6:5 for a winning blackjack. This gives the player worse odds.

Example:

  • You wager $500 at a 3:2 Black Jack table and win with a black jack. You are paid $750 and have a total of $1,250.
  • You wager $500 at a 6:5 Black Jack table and wins with a black jack. You are paid $600 and have a total of $1,100.

Of course, getting paid more than 3:2 for a winning blackjack gives the player better odds.

Example: You wager $500 at an 8:5 Black Jack table and win with a blackjack. You are paid $800 and have a total of $1,300.

In reality, a blackjack table paying 8:5 on winning blackjacks would most likely have pretty player-unfriendly rules in other areas of them game to keep the house edge up. It is always important to take all rules into account when you try to determine the odds offered by a specific blackjack table. Staring at just one of the many rules can lead you astray and trick you into thinking that the odds for the player are better than what they really are.

Dealer hits on soft 17

Unlike a player, a blackjack dealer is not allowed to make decisions regarding her own hand. At most blackjack tables, the dealer must hit on 16 points and lower and must stay at 17 points and higher.

But what happens if the 17 point hand is a soft 17? The rules for soft 17 varies from one blackjack table to the next, and this is something that impacts the odds for the player.

If you see H17 printed on the blackjack table, it means that the dealer must hit on a soft 17. (H = hit.)

If you see S17 printed on the blackjack table, it means that the dealer must stay on a soft 17. (S = stay.)

With everything else equal, changing the rules from H17 to S17 will give the player better odds.

Dealer wins ties

This is a horrible rule that creates horrible odds for the player. Even if the dealer “only” wins ties on 19 points and below, it is a horrific rule and blackjack tables that employ this rule should be avoided. There really is no reason to play at these tables. They tend to be found in night clubs rather than in proper casinos.

Doubling

black jack 3In some casinos, you are allowed to double on any two-card hand. In others, you are only allowed to double on a two-card hand worth 9 points, 10 points or 11 points. There are even a few casinos that are stricter than this, e.g. only allowing you to double on 10 points and 11 points, not allow doubling down on soft hands, and not permitting a player to double after a split.

The stricter the rules are for doubling, the more opportunities are lost for the skilled blackjack player that can identify situations where doubling down would have been the right way to go from a mathematical perspective.

Doubling after a split

Some casinos will not allow a player to double down after a split. This rule is bad for the players, since it increases the house edge.

Splitting aces

At many blackjack tables, you only get one new card on each ace when you split aces.

  • If the casino allows players to recieve more than one card on a split ace, that reduces the house edge and gives the players better odds.
  • If the casino allow players to re-split aces, that reduces the house edge and gives the players better odds.