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6 Blackjack Mistakes Most Players Make


A former casino pit boss shares his secrets

Blackjack is one of the best bets in the casino—if you play it well. Make smart decisions, and the house’s edge on each hand can be well under 1%. Trouble is, most blackjack players make mistakes that significantly decrease their odds of winning.

One way to avoid these mistakes is to purchase a blackjack basic strategy card in the casino’s gift shop—these typically cost just a dollar or two—then follow its instructions. Most casinos even ­allow players to refer to these cards at the table, particularly if the player requests permission to do so…is not playing for particularly high stakes…and doesn’t take too long studying the card before each decision.

But if your pride prevents you from playing with a strategy card in front of you, at least avoid the following common blackjack mistakes…

Mistake: Taking insurance. This is almost never worth doing.

When the dealer’s up card is an Ace, he/she will ask if any player wants to take insurance. Players who wish to do so put out an additional bet that is worth half the amount of their original bet. If the dealer then reveals a blackjack, he will pay off these insurance bets at 2:1, covering players’ losses on the hand.

But while insurance pays 2:1, the odds that a dealer showing an Ace has a blackjack are even steeper—approximately 9:4 against. That means declining the insurance is the better move in the long run. This is true regardless of what cards you have been dealt.

Mistake: Standing on 12 when the dealer shows a 2 or 3. The smart move is to hit.

The cards 2, 3, 4, 5 and 6 are sometimes called “dealer bust cards” because the dealer is particularly likely to go over 21 when one of these is his up card. Thus players often stand on 12 when the dealer has one of these—that way the player avoids the possibility that he will bust before the dealer has a chance to do so. But not all dealer bust cards are created equal—while the odds of a dealer bust are high enough that it makes mathematical sense to stand on 12 when the dealer shows a 4, 5 or 6, you’re better off hitting 12 when the dealer has a 2 or 3.

Mistake: Hitting a pair of 4s when the dealer shows a 5 or 6. The smart move is to split the 4s—that is, divide them into two separate hands, doubling your bet.

It can be tempting to hit a pair of 4s because doing so feels safe—you won’t bust even if you are dealt a 10. But when the dealer shows a 5 or 6, the odds that he will bust are so high that it actually makes more sense to split your 4s. That lets you get an extra bet on the table and doubles your payout if the dealer does indeed go over 21.

Mistake: Standing on a 16 when the dealer shows an Ace. The smart move is to hit. (Or split, if your 16 is a pair of 8s—see below.)

It might seem counterintuitive to hit on 16—you will bust if you draw any card above five. But if you have a 16 and the dealer is showing an Ace, the odds are against you no matter what you do, and it turns out that hitting makes you slightly less likely to lose. In fact, it generally is worth hitting on 16 if the dealer is showing any card 7 or above.

Alternative: Some casinos offer a “surrender” option, which lets the ­player give up his hand after the initial cards are dealt and recover half the money he has bet (assuming that the dealer does not have a natural blackjack). Surrender usually is not offered at low-minimum tables, but there’s no harm in asking the dealer. If surrender is available, take advantage when holding a “hard” 16—that is, one that does not include an Ace—and faced with a dealer showing a 9, 10 or Ace…or when holding a hard 15 and faced by a dealer showing a 10.

Mistake: Splitting 10s.* The smart move is to stand on a pair of 10s, regardless of what the dealer is showing.

Some players split 10s when the dealer is showing a bust card such as a 5 or 6. But while this might seem like a great opportunity to double your bet while the dealer is in a tough spot, it turns out you’ll win more over time by just playing the two 10s as a hand of 20.

Also: Never split a pair of 5s either—double down (see below) if the dealer is showing anything less than 10, or hit if the dealer is showing a 10 or an Ace. Conversely, it is always worth splitting Aces or 8s regardless of what the dealer is showing.

Mistake: Doubling down on 11 when the dealer shows an Ace.

When a player “doubles down,” he doubles his initial bet and receives ­exactly one more card for his hand. Doubling down is almost always wise when your initial two cards total 11. After all, there’s a solid chance that you will be dealt a 10, giving you a total of 21.

But contrary to the conventional wisdom, there is a time when doubling down is not the smart move with an 11. If the dealer is showing an Ace, you are better off just hitting…usually. The wrinkle—this advice assumes that the dealer will stand on “soft 17”—that is, he will not draw another card if he holds an Ace and a 6, which total 17. At some casinos, the dealer hits on a soft 17, in which case doubling down on 11 is the right move. (What the dealer does with a soft 17 can vary even from table to table within a single casino. Look for a sign on the table listing this and other rules. When possible, play at a table where the dealer stands on a soft 17—this slightly improves players’ odds.)

If remembering what to do with an 11 against an Ace gets too confusing, at least remember that at any table it is worth doubling down on 11 against all non-Ace dealer cards…on 10 if the dealer is showing a 4, 5 or 6…or on 9 if the dealer is showing a 5 or 6.

To double down, simply place chips equal in value to your original bet next to that first bet. (If you have a pair, say “double down” as you do this so that the dealer doesn’t mistake your bet for an attempt to split the pair.)

Choose the Right Blackjack Table

There is one costly mistake that many blackjack players make before they are even dealt a card—they sit down to play at the wrong table. In the past several years, casinos have quietly reduced the payout on blackjacks at some tables. Traditionally, when a player hits a blackjack—that is, when his initial two-card hand adds up to 21—he receives 3:2 on his bet, such as $7.50 on a $5 bet. But some tables now pay just 6:5, which is just $6 on a $5 bet.

Do not play blackjack at a 6:5 ­table—this one rule change makes it nearly impossible to beat the house even if you play very well.

Usually there is a placard at the ­table that lists this and other table rules. If you do not see one, ask the dealer, “Is this 6 to 5 or 3 to 2 blackjack?”

If all of the blackjack tables with stakes that you consider affordable at a casino are 6:5 tables, choose a different casino or do not play blackjack at all.

*When blackjack players refer to a “10,” they mean any card worth 10, which ­includes both 10s and face cards.


Thomas ­Gallagher, former Las Vegas casino pit boss who now serves as a gambling coach and consultant. He is author of numerous gambling workbooks, including Blackjack Magic, available through his website,

Date: November 1, 2015 Publication: Bottom Line Personal