Blackjack is a very popular game amongst both the offline and online gaming communities mainly because the player is required to make several decisions every hand which will affect the outcome of the game. Therefore it is perceived to have more skill than other casino games (not including poker), however for advanced and sensible players, decisions will rarely deviate from the best blackjack strategy, known as basic strategy. In blackjack, the dealer has no decisions to make so optimal player decisions are always the same, which is why basic strategy works.
Once the player has grasped the basic rules of blackjack the next thing to learn is how to optimise your chances of winning. Predictably, there are countless theories and strategies designed to give the player an edge against the dealer but, just as predictably, none will actually give the player an advantage over the dealer apart from those considered illegal by the casinos. I am of course referring to card counting in which is banned by most casinos. Card counting will not be discussed here as it is not applicable to online blackjack. Rather, the strategy laid out here will be almost exclusively based on basic strategy.
WHAT IS BASIC BLACKJACK STRATEGY?
Quite simply, basic strategy is the optimal way to play blackjack. It has been devised using statistical probabilities to calculate the best possible move in any particular circumstance according to your cards and the dealer's starting card. The aim of basic strategy is obviously to win as often as possible but also to maximise your winnings (through double-down), to reduce the chances of busting, and also in some circumstances, to minimise your expected losses (through surrender or when choosing not to double). Of course, when playing any casino game, including blackjack under standard rules, the house will always have a slight edge but following basic strategy will significantly reduce this edge. It does not take into consideration any other cards which may have been seen in previous hands or other players' cards which would have a slight significance on subsequent cards. This is the basis of card counting which will not be discussed here. However, this is not a significant consideration for online blackjack as each round is played with a newly shuffled deck usually from a 6-deck pack. This means there is usually a 312 pack deck with 24 of each card, so unless you are considering the odds of one particular card which has appeared an incredibly large number of times already in that hand (e.g. 15 or more) then it is negligible.
The statistical calculations and permutations which form the basis for the basic strategy table will not be discussed here. The table is a robust playing guide and explaining how each decision has been arrived at is largely irrelevant as the end result - the recommended decision - will remain the same. If you are new to blackjack, it is recommended that you keep this guide close by when playing online, either on your computer screen or printed out, as a quick reference guide. You will find that the more you play, the less often you will need to refer to it as you being to learn the optimal decision for al possible situations. Eventually, you will be able to play basic strategy blackjack without even looking at the chart! Of course, if you are playing blackjack live at a casino, they might frown upon the use of a chart at the table. Some casinos will allow you to take a printed reference sheet with you (some will even have it available free for players to use at the table!) but almost certainly none will allow it on a computer or mobile device.
If you look at the basic strategy guide here you will see general patterns about where to hit and stand. For example, always hit (sometimes double-down) when your hand is below 11 (obviously, as you cannot bust) and always stand on 17 and above (unless it's a soft hand). The best way to learn basic strategy by heart is not to learn all the possible hands but rather focus on the borderline hands. For example, when the dealer has 7 the recommended strategy for the majority of player hands changes dramatically from when a 6 is shown.
BLACKJACK STRATEGY RISK
If a player follows basic strategy and does not deviate from its path then the theoretical return to player (RTP) under standard rules is 99.63%. This a very high RTP and will usually be the highest within a given casino, both online and offline, so it is perhaps no wonder that blackjack is such a hugely popular game. However, although the RTP is high in blackjack, the variance is low as the highest payout possible in one hand is limited to 3:2 (blackjack). In comparison to slot games for example where players are sometimes able to win up to several thousand times their stake, blackjack players are unlikely to win a huge amount in one session.
Remember that basic strategy does not guarantee that you will win money. In fact, even if you follow this guide to the letter the RTP will always be below 100%. Also, it is important that you stick with it, even if you get a run of bad results. Players who play according to basic strategy will always outperform those who make their decisions based on gut instinct in the long run. Similarly, it is a common misconception that basic strategy should only be used on the first card drawn - this is not true. It should be followed during every decision.
SPLIT
Always split aces. Although the player will only receive one further card on both aces, 11 is such a strong starting number that even the limit of one further card stall makes it the best decision to make. Similarly, always split 8-8. For all other circumstances in which splitting is recommended, refer to the basic strategy chart.
INSURANCE
Quite simply: never take insurance. It is more profitable in the long term to risk losing your initial stake than to protect it against the dealer hitting blackjack.
DOUBLE-DOWN
Doubling-down is perhaps the single best way of reducing the house edge when playing a blackjack session. By doubling your stake in a very strong position you can capitalise on these positions of strength and swing the balance of power away from the dealer. As a rule of thumb, you should always double-down on 11, except when against an ace and you should also double on a 10 (also 5-5), except when against an ace or a dealer's 10. You should double-down on 9 against a dealer's 3, 4, 5, and 6. As explained in the rules, some tables restrict doubling to 9, 10, and 11, but for those that allow it on other hands (both early and late) there a number of situations in soft hands in which it is recommended to double-down. Finally, as shown on the chart, if it is not possible to double-down you should hit apart from four situations where it is recommended to stand: when a player has soft 18 and the dealer has either 3,4,5, or 6.
SURRENDER
As explained in the rules section, surrender allows the player to escape from a particularly unfavourable position in which neither hitting or standing are preferable. In these exceptional circumstances, surrendering your hand and sacrificing half your stake will result in losing less in the long term. The only times basic strategy recommends the player to surrender is when the player has hard 15, dealer has a 10 or when the player has hard 16 and the dealer has either 9, 10, or A. If the player is not permitted to surrender (if the table is restricted to early surrender only or if it is not allowed at all) they should hit.
SIDE BETS
Many blackjack games, both online and offline, give the player the option to participate in one or more side bets that operate separately but alongside a normal hand. Note: players must place a stake on the 'normal' blackjack hand if they want to participate in any side bets. In the blackjack rules section, two common side bets are explained, Perfect Pairs and Luck Lucky, however variations of these side bets plus countless other special ones exist, some exclusive to certain casinos only. Generally speaking, side bets are not recommended. They almost never offer value to the player and the house edge is much larger than the normal game.
NUMBER OF DECKS
The number of decks used by the dealer in blackjack has a very slight effect on the house advantage.
Number of decks House advantage:
Single deck 0.17%
Double deck 0.46%
Four decks 0.60%
Six decks 0.64%
Eight decks 0.65%
As you can see, the difference is pretty small but generally speaking the fewer decks used, the better. It is very rare to see double or eight deck games online and the most common being four or six, however, some sites do offer single deck blackjack. Single deck blackjack is often limited to one hand only and the cards are shuffled after every hand so the advantage here would only be found during exceptional hands in which a large number of one particular card, e.g. ace, appears many times and is an important factor in further decisions.
