Top Ten Blackjack Basic Strategy Mistakes

If you play blackjack for an hour or two, your results will be pretty unpredictable. You may win a lot, or you may lose a lot. Most of the time, you’ll be somewhere in between. In the short-term, good luck or bad luck decides whether you’ll be a net winner or loser. However, if you average out your results over many hours, it becomes clear that playing smarter will save you a lot of money.

A typical blackjack player loses 2% of his total bets to the casino over the course of many bets. That may not sound like much, but it is four times as expensive as it need be. A basic strategy player in a typical 6-deck game loses approximately 0.5%. Playing a 2-deck game instead cuts the house edge to about 0.2%, and a single-deck game with decent rules is basically a break-even game.

If you are a $10 bettor playing a typical 6-deck game as offered on the Las Vegas Strip, you can expect to put around $600 in action in an hour of play. An average player will lose 2% of this, or $12 an hour. A player using the correct basic strategy will lose 0.5% of $600 instead, or only $3.

What makes up this difference? What follows is a list of the most common errors I see made by blackjack players. The examples assume you are betting $10 per hand at a 6-deck game, where the dealer stands on all 17s and double after split is allowed.

12 vs dealer 3
The Correct Play: HIT

Lots of players hate to hit 12 here, especially in the third-base seat. They’ll talk about “taking the dealer’s bust-card”, and so forth. The casinos love to hear that.

On average, standing with 12 against a 3 loses $2.55. Hitting loses slightly less at an average $2.31. So, hitting is better by 24 cents.


What’s it worth?
$0.24 (HIT)
(Ace,7) vs dealer Ten
The Correct Play: HIT

Most players misplay this hand. They figure, why hit an 18? Well, I’ll tell you why. Eighteen is a poor hand. It’s a loser here no matter what. Yes, you’ll often make the hand worse by hitting it, and you may have to hit it several times. Nonetheless, the numbers don’t lie:


What’s it worth?
$0.37 (HIT)
Taking “Even Money” on Blackjack
The Correct Play: DON’T

Dealers will tell you “It’s the only sure bet in the casino.” Well, yes, it is a sure thing. But it comes at a price. Even money is just insurance by another name, and unless you’re counting cards, it’s a sucker bet.

Taking Even Money:
$10.00 (every time)
Not Taking Even Money:
$10.39 (on average)

What’s it worth?
$0.39 (DON’T)
12 vs dealer 2
The Correct Play: HIT

This is just like 12 vs 3, with the same silly excuses. But now, the numbers are even more convincing…


What’s it worth?
$0.44 (HIT)
(8,8) vs Ten
The Correct Play: SPLIT

This is a popular one. Many players hate to put more money on the table in a losing situation. Sound reasonable, right? Well, sometimes not. Here’s a great example. By wagering another $10, we get rid of a truly horrible hand of 16, and start with two run-of-the-mill bad hands of 8. We’ll still lose money, but we’ll lose less.


What’s it worth?
$0.52 (SPLIT)
(Exception: In the European No-Hole-Card game, players should NOT split this hand because the dealer might end up with blackjack. In the US-style game, the dealer has already checked for blackjack.)
11 vs dealer Ten
The Correct Play: DOUBLE

It’s one thing to be reluctant to put more money up in a losing situation, but many people also choose to not double 11 vs a dealer Ten, despite having the ‘best of it’.


What’s it worth?
$0.60 (DOUBLE)
(Exception: In the European No-Hole-Card game, players should NOT double this hand.)
(Ace,7) vs dealer 9
The Correct Play: HIT

This is another mistake that most players make. And, it’s starting to get pretty expensive at $0.85 per error. Don’t even hesitate. Hit it.


What’s it worth?
$0.85 (HIT)
(8,8) vs dealer Ace
The Correct Play: SPLIT

This is just mistake number 6 revisited, but it’s more expensive. It’s the same old reluctance to buy your way out of a bind.

There are three ways to play this miserable hand:


What’s it worth?
$1.28 (SPLIT)
(Exception: In the European No-Hole-Card game, players should NOT split this hand.)
(Ace,6) vs dealer 7
The Correct Play: HIT

I guess some people just want to play for a push here. But, here’s a rare opportunity. You can actually turn a losing situation into a winning one on average by hitting this hand. It’s no coincidence that this ranks at number 2. It’s the second most expensive mistake on the list. Just hit it.

Wins $0.55

What’s it worth?
$1.59 (HIT)
(Ace,Ace) vs dealer Ten
The Correct Play: SPLIT

Fortunately, I don’t see this mistake too often. But, I do see it occasionally. When you split Aces, you’re only allowed to draw one to each. Some misguided players think this makes it a bad play. If it bothers you, just think of it as doubling down on two elevens instead. And, consider what starting with a hand of 2 or 12 is likely to produce. This one is a real no-brainer. Ante up and split. Every time.


What’s it worth?
$2.48 (SPLIT)
(This play you make even in the European No-Hole-Card game. Splitting Aces is strong enough to warrant the risk.)

Well, that’s it. The ‘Hall of Shame’ for common strategy mistakes. As you can see, even at $10 a hand, this stuff starts to add up.

If every player learned the correct basic strategy, casinos couldn’t afford to offer the game as we know it. The floor space would be converted to slot machines in a flash. But it seems there’s a never ending supply of players who prefer to play by the seat of their pants, and keep the casinos flush with cash.

Best of luck, -Ken-

Details for the obsessive: The dollar amounts calculated in this article assume a 6-deck S17 DAS game. Player hand of 12 is assumed to be (Ten,2). Player hand of 11 is assumed to be (5,6). Other compositions yield very slightly different amounts.

10 comments on "Top Ten Blackjack Basic Strategy Mistakes"

  • Andrew C said:

    Hi Ken,
    The Casino (ENHC) that I visit has a good rule – if the player splits or doubles & the dealer gets Blackjack, the player only loses the 1st bet, so this will change the Basic Strategy a little. I’m guessing that in this case I should double a hard 10 against dealers 10, but not sure about splitting Aces against a dealers Ace? Oh, I should also mention that you can only split to two hands.

  • What would you do if you have a hard 11 and dealer is showing an Ace? 6-deck game, dealer hits on soft 17. I would still double, am I wrong?

    • Correct, when the dealer hits soft 17, you still double 11vA. If the dealer stands on soft 17, you just hit (unless you are playing a one or two deck game.)
      For exact strategies for your rules, see the Strategy Engine.

  • BIGBOB said:

    On the 8,8 hands if I can surrender am I saving or loosing money vs the 10 and the A.??


  • BIGBOB said:

    On the 8,8 hands if I can surrender am I saving or loosing money vs the 10 and the A.??


  • Paul said:

    One I do not understand. I am instructed to hit the 11 against an ace even though the dealer has checked that he does not have BJ.? Can anyone help me understand.

  • Hi Ken,
    Recently, during a visit to Genting Casino in Malaysia, I found out that they don’t offer Blackjack games anymore to ordinary players like me.The staff told me that it is only offered to high stakes players in the VIP rooms.Instead they offer pontoon and other variations of Blackjack games in the main Hall.

    Yours Sincerely,

Leave a Reply

Comment can't be blank.

A valid name is required.

A valid URL is required.

Top 10 Blackjack Strategy Mistakes

What are some common mistakes made by blackjack players?  Subscribe and download our detailed report to find out.

You have Successfully Subscribed!