I can always spot a novice blackjack player by the way he or she plays the two-card hand, ace and seven. The latter is known as a soft 18 because it contains the ace counted as 11. The hand is frequently misplayed because most blackjack players believe they should stand when they have an 18. This is true for hands that total 18, which do not contain an ace (for example, 10 and eight), or if the ace is present, it counts as one (for example nine, six, ace, two). But in the case of the soft 18, you would be making a mistake by always standing.
For example, if you were dealt a soft 18 and the dealer’s upcard is a nine, 10, or ace, you are better off hitting than standing. A total of 18 just isn’t good enough against those powerful dealer upcards. You gain $8 more per $100 wagered on average when you hit the soft 18 vs. standing against the dealer’s nine. Against the dealer’s 10, you will gain $4 more and against the ace, about 40 cents. This may not seem like much, but remember, your goal when you play blackjack in a casino is to make the best percentage playing decision to maximize your gains (or in some playing situations, minimize your losses).
Now, how about the playing situation of being dealt a soft 18 against a dealer upcard of either three, four, five, or six? In this situation, your best percentage play by far is to take advantage of the double down option. By doubling your bet, you are essentially putting more money on the table when the dealer is most vulnerable to break. You can’t possibly break by drawing one card since you can always count the ace as one (ace, seven, nine would be 17). Do not pass up the opportunity to double down on soft 18 against these dealer upcards. This is a very profitable blackjack play to make.
In the case you are dealt a soft 18 and the dealer’s upcard is either a two, seven, or eight, then your best play in this situation is to stand. Your gain per $100 bet favors standing vs. doubling by $23 against the seven, $7 against the eight, and a few cents against the two. Remember, your goal is to maximize your profit potential or gain on each hand of blackjack dealt to you.
Let’s summarize the correct way to play the soft 18 when it is dealt to you.
You should hit when the dealer upcard is a nine, 10, or ace.
You should double down when the dealer upcard is a three, four, five, or six.
You should stand when the dealer upcard is two, seven, or eight.
The above strategy is valid for single-deck, two-deck, and even six- or eight-deck games. It’s a smart strategy to follow if you are serious about winning.