Blackjack games offer very high average returns to the player, which usually are over 99%. However, the condition is that players make optimum moves. One optimum move is double. After seeing his first two dealt cards and the dealer’s up card the player can double his wager. In certain situations the chances of winning are very much higher. If the player does not exploit such situations by doubling his wager then he will never be able to reach the average return of over 99%. The player will not win every time after doubling. He has to be prepared for that. Optimum blackjack strategy is based on what gives the best chance of winning, rather than the actual outcome.

The opportunity of doubling the wager comes with a price. After the player doubles he has to take one additional card and cannot take more than one additional card. After taking the additional card the player has to stand no matter what his hand value. The dealer plays his hand as per the rules of the particular blackjack variant being played. This condition makes doubling strategy very simple because it narrows down the range of possible outcomes.

There are two types of doubling strategy in blackjack. The simple strategy takes into account only the players dealt cards and the dealer’s face up card. It is suitable for beginners. Expert players however use the advanced doubling strategy. This also factors in the number of decks and the other rules. The other rules include whether the dealer hits or stands on soft 17 and whether he checks for blackjack before the player makes his first move. The advanced strategy has to be memorized because it has been generated through computer simulation. The simple strategy can be reasoned out and is being discussed here.

The advantage to the player derives from two situations. The first is the strength of his hand and the second is the weakness of the dealer’s hand. The decision making process assumes that the next card dealt has a high probability of being a 10 value card. If the player has a hand value of 11 then he has a very good chance of reaching a value of 21. Hence he should always double in such a situation. If the player has a hand value of 10, he can expect to be in a strong position after doubling. However, if the dealer’s up card is a 10 value card or an ace, the player’s position is somewhat weakened. Hence with a hand value of 10 the player should double unless the dealer has a 10 value card or an ace.

If the dealer’s up card is a 4, 5 or 6 then he will very likely draw two cards and go bust. Therefore this situation is usually a good one for doubling. However the player has to guard against his going bust. This is likely if his hand value is 12 or more. Also hand values of 7 or less weaken the player’s situation. Therefore in this situation the player should double if his hand value is between 8 and 11 and the dealer’s up card is between 4 and 6.

Once the player is comfortable with the simple strategy he can move to the advanced strategy.