Blackjack When To Double
In blackjack, double down is when you actually double the wager when you get the first two cards. As the cards are dealt out, you will have the option if permitted by the rule. In case you win the bet, you will win double your actual wager.
If you are new to the game of blackjack then one of the best ways to start out is by familiarizing yourself with the basic strategy of the game. Basic blackjack strategy charts can help make it easy to learn the basics of when to hit, when to stand, when to double down and when to split pairs in any situation.
Basic blackjack strategy charts are tables that list possible hand values on one axis and possible dealer upcard values on the other axis. Based on the value of your hand and the value of the dealer's upcard you can easily determine which move you should make. Strategy charts are based upon a number of factors including the probability of the dealer busting or getting blackjack, the probability of the player busting or getting blackjack and a number of other factors.
You will see from looking at a basic chart that there are several hands that have easy and straightforward decisions that you should make every time. For instance, when you are dealt a hand worth a hard total of 17 through 21 (not including an Ace) you should always stand. On the other hand, when your hand is valued at 5, 6, 7 or 8 you should always hit. It doesn't matter what upcard the dealer is showing, you should always stand or always hit in these instances.
- Blackjack double down allows you to double your bet in the middle of a blackjack hand in exchange for an additional card. Despite how exciting the doubling down option might be, it’s also risky. If you get a second low card, it would mean you can’t hit again, indicating that the probability you’d beat the dealer is low.
- According to a mathematical analysis on Double Up Blackjack prepared by Charles Mousseau for the game’s inventor, the house edge in the cases when the dealer hits on a soft 17 sits at around 0.313%. And there’s some more as this variant allows players to split, re-split, except Aces, and double up after splitting.
- Feb 14, 2020 There’s only one point in a game of blackjack when you have the opportunity to double down – directly after your initial two cards have been dealt. At this point there are three groups of hands.
- Blackjack Strategy. When the value of dealer's revealed card is 4,5 or 6, it may be fruitful to double your bet with an Ace and 4 in hand. You may want to surrender if you have 16 in your hand while the dealer has a 9,10 or A. You should always split if you have a pair of Aces.
Other decisions are not so black and white. For instance, when you have a hand with a value of 12 blackjack strategy charts will tell you to hit on everything except when the dealer is showing a 4, 5 or 6, in which case you should stand. The reason for this is that the dealer is likely to bust when he shows a 4, 5 or 6. By studying basic strategy charts you can learn the best decision to make in any hand of blackjack.
| Your hand | Dealer's face-up card | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | A | |
| Hard totals (excluding pairs) | ||||||||||
| 17-20 | S | S | S | S | S | S | S | S | S | S |
| 16 | S | S | S | S | S | H | H | SU | SU | SU |
| 15 | S | S | S | S | S | H | H | H | SU | H |
| 13-14 | S | S | S | S | S | H | H | H | H | H |
| 12 | H | H | S | S | S | H | H | H | H | H |
| 11 | Dh | Dh | Dh | Dh | Dh | Dh | Dh | Dh | Dh | H |
| 10 | Dh | Dh | Dh | Dh | Dh | Dh | Dh | Dh | H | H |
| 9 | H | Dh | Dh | Dh | Dh | H | H | H | H | H |
| 5-8 | H | H | H | H | H | H | H | H | H | H |
| Soft totals | ||||||||||
| 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | A | |
| A,8 A,9 | S | S | S | S | S | S | S | S | S | S |
| A,7 | S | Ds | Ds | Ds | Ds | S | S | H | H | H |
| A,6 | H | Dh | Dh | Dh | Dh | H | H | H | H | H |
| A,4 A,5 | H | H | Dh | Dh | Dh | H | H | H | H | H |
| A,2 A,3 | H | H | H | Dh | Dh | H | H | H | H | H |
| Pairs | ||||||||||
| 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | A | |
| A,A | SP | SP | SP | SP | SP | SP | SP | SP | SP | SP |
| 10,10 | S | S | S | S | S | S | S | S | S | S |
| 9,9 | SP | SP | SP | SP | SP | S | SP | SP | S | S |
| 8,8 | SP | SP | SP | SP | SP | SP | SP | SP | SP | SP |
| 7,7 | SP | SP | SP | SP | SP | SP | H | H | H | H |
| 6,6 | SP | SP | SP | SP | SP | H | H | H | H | H |
| 5,5 | Dh | Dh | Dh | Dh | Dh | Dh | Dh | Dh | H | H |
| 4,4 | H | H | H | SP | SP | H | H | H | H | H |
| 2,2 3,3 | SP | SP | SP | SP | SP | SP | H | H | H | H |
The above is a basic strategy table for 3 or more decks, dealer stands on soft 17, double on any 2 cards, double after split allowed, dealer peeks for blackjack, and blackjack pays 3:2. Key:
- S = Stand
- H = Hit
- Dh = Double (if not allowed, then hit)
- Ds = Double (if not allowed, then stand)
- SP = Split
- SU = Surrender (if not allowed, then hit)
- Appendices
- Miscellaneous
- External Links
Introduction
Rule variations will have an effect on the player's expected return. The numbers below show the effect on the player's return under various rules and after taking into consideration proper basic strategy adjustments. These changes are relative to the following rules: eight decks, dealer stands on soft 17, player may double on anyfirst two cards, player can double after splitting, playermay split to 4 hands.
Blackjack Rule Variations
| Rule | Effect |
|---|---|
| Blackjacks pay 2 to 1 | +2.27% |
| Triple down on any two cards | +1.64% |
| Five cardCharlie1 | +1.46% |
| Optional half win for 5-card Charlie9 | +0.77% |
| Suited blackjacks pay 2 to 1 | +0.57% |
| Player 21-points is automatic winner | +0.54% |
| Single deck | +0.48% |
| Early surrender against ace | +0.39% |
| Player 21 vs. dealer blackjack is a push | +0.35% |
| 5-card win pays 3-2 | +0.33% |
| Blackjack tie pays 3 to 2 | +0.32% |
| Six-card Charlie pays 3 to 2 | +0.31% |
| Early surrender against ten | +0.24% |
| 5-card (or more) 21 automatically pays 2 to 1 | +0.24% |
| Player may double on any number of cards | +0.23% |
| Ace and 10 after splitting aces is a blackjack (paying 3-2) | +0.21% |
| Player may draw to split aces | +0.19% |
| Double deck | +0.19% |
| Six card Charlie1 | +0.16% |
| Player may double, double for less, or stand after splitting aces | +0.15% |
| Tied blackjack pays 1-2 | +0.11% |
| Ace and 10 after splitting aces is a blackjack (paying 6-5) | +0.11% |
| Double Down Rescue | +0.10% |
| 6-card win pays 2-1 | +0.09% |
| Player may resplit aces | +0.08% |
| Player may double or stand after splitting aces | +0.08% |
| Late surrender against ten | +0.07% |
| Four decks | +0.06% |
| 7-card win pays 5-1 | +0.05% |
| 777 pays 3 to 1 automatically | +0.05% |
| Five decks | +0.03% |
| 777 pays 2 to 1 automatically | +0.03% |
| Six decks | +0.02% |
| Seven card Charlie1 | +0.01% |
| Late surrender against ace | +0.00% |
| Dealer must stop with six cards | +0.00% |
| Late surrender after splitting | +0.00% |
| Split to only 3 hands | -0.01% |
| No-peek: ace showing2 | -0.01% |
| BB+13 | -0.01% |
| Dealer secretly goes first5 | -0.02% |
| OBBO4 | -0.03% |
| European no hole card (splitting)7 | -0.03% |
| European no hole card (doubling)7 | -0.08% |
| Player may double on 9-11 only | -0.09% |
| No-peek: ten showing6 | -0.10% |
| Player may not resplit | -0.10% |
| European no hole card7 | -0.11% |
| Player may not double after splitting | -0.14% |
| Player may double on 10,11 only | -0.18% |
| Player may not split aces | -0.18% |
| Dealer hits on soft 17 | -0.22% |
| Blackkjack pays 7-5 | -0.45% |
| Player may not split | -0.57% |
| Red blackjack pays 2-1, Black blackjack pays 3-2, Mixed blackjack pays 1-1 | -0.57% |
| Blackjack pays 6-5 | -1.39% |
| Player may not double | -1.48% |
| Player loses 17 ties | -1.87% |
| Player may not double nor split | -1.91% |
| Blackjacks pay 1 to 1 | -2.27% |
| Player loses 17,18 ties | -3.58% |
| Player loses 17-19 ties | -5.30% |
| Dealer bust on 22 is a push8 | -6.91% |
| Player loses 17-20 ties | -8.38% |
| Player loses 17-21 ties | -8.86% |
Notes
Blackjack When To Double Down
- A 'Charlie' is an automatic winner. For example the five-card Charlie rule means the player automatically wins with 5 cards, as long as he didn't bust.
- Dealer does not peek for blackjack with an ace up. If dealer has a ace-up blackjack, player loses all bets made, including from doubling and splitting. A 10-up blackjack will be revealed immediately after peeking, and the player will lose only his original wager, except a blackjack tie will push.
- BB+1 refers to an Australian rule, in which the player will lose all busted bets, plus one unit, if the dealer gets a blackjack. For example, if the player splits 8's to three hands of a 20, (doubled) 19, and a busted hand, and the dealer get a blackjack, then the player will lose 2 units, one for the busted hand, and one from the remaining 3 units on the table. There is a great deal of confusion for the term for his rule, some sources calling it 'OBBO,' for Original and Busted Bets Only.
- OBBO stands for Original Bets and Busted Only. 'Original Bets' means each original bet per hand. So, if the player bet $5 and split to three hands, he would have three original bets of $5 each. As far as I know, the OBBO rule is confined to some parts of Australia and Malaysia. In the example above, the player would lose 3 units under this rule, one for the busted hand and two for the number of unbusted hands. The term is discussed in depth in the bookThe Pro's Guide to Spanish 21 and Australian Pontoon by Katarina Walker.
- This strange rule is actually followed in Pennsylvania, on Shufflemaster TMS-300 video multi-player blackjack games. State law prohibits one player taking the cards of another player. The way they implement this rule is to give every player, and the dealer, a separate shoe. The dealer plays out his hand first, secretly, and the results stored in memory. Then the cards used by the dealer are removed for each player shoe. When all players have finished acting, the game shows what cards the dealer drew already. According to Shufflemaster, the effect of this rule is 0.02% in favor of the dealer. Shufflemaster wishes to add this rule is part of a patent-pending technology.
- Dealer does not peek for blackjack with a 10 up. If dealer has a 10-up blackjack, player loses all bets made, including from doubling and splitting. An ace-up blackjack will be revealed immediately after peeking, and the player will lose only his original wager, except a blackjack tie will push.
- Dealer does not take a hole card, or never peeks at it if he does. If the dealer has a blackjack, then player loses all bets made, including from doubling and splitting, except a blackjack tie will push. The cost of this rule to the player is 0.08% when doubling, and 0.03% when splitting. This breakdown is important in the case of Galaxy casinos in Macau, where the player only loses the original bet when doubling, but everything when splitting, if the dealer gets a blackjack.
- The push on a dealer 22 rule is a legally protected rule. The rights belong to the owner of Blackjack Switch.
- This rule can be found at the Pharaoh's Palace in Macau. The player may invoke the rule before the dealer checks for blackjack. The effect shown is based on the dealer not taking a hole card.
Blackjack Double Strategy
Written by: Michael Shackleford