When Shouldn't You Double Down with a Proper Doubling Hand?

In blackjack, about once every eleven hands you'll be dealt something that's normally a proper double down. Yet, from time to time for various reasons we all get an ominous feeling that says, "This time, don't do it!"

The impulse may come from the fact that we've just lost a tough hand -- or perhaps we have an unusually large bet up and don't feel comfortable risking twice that amount all at one time. Reasons like these, of course, should never enter into such a decision because they don't affect your odds to win the hand.

Sometimes we don't feel comfortable doubling down because of the last card -- or the last few cards that just came out of the shoe. After all, if you're looking for a 10 and three straight 10s just came out in front of you, that has to hurt your chances to catch your own 10.

Well, you may be surprised to learn that with most hands, you'd still be making a mistake if you took matters into your own hands even for that reason. It's pretty seldom that you'll see enough cards right there on the board to turn a basic strategy double down into an incorrect play.

With a six-deck shoe there are however three -- and only three -- such hands for which this would be true. I want to point out those three hands here today so that you stop going "anal retentive" on other perfectly good double downs.

Let's start by explaining that the basic strategy counts, then eliminates three cards from the shoe -- your two starting cards and the dealer's up-card. Basic strategy just colors them gone and then assumes all 309 other cards from the six decks have an equal chance of coming out next. That's a very good way to do things -- usually.

Sometimes, though, enough extra high cards hit the board that would've turned a double down into a hit if the basic strategy knew those cards were gone. This is true only on close doubles that start out as a marginal decision to begin with. For example, let's say you have:

Dealer
3/?

You
7/2

Normally, you should double down with this hand, but it is a pretty close decision. In fact, if five extra 10s are strewn around the board, doubling down would actually be wrong!

What do I mean by, "five extra 10s"? The method a basic strategy player should use to determine this is called the "Babies vs. 10s Technique". Babies are all the 2s, 3s, 4s and 5s while the 10s are all the 10s, Jacks, Queens and Kings. Notice that there are the same total number of Babies as 10s in a full pack of cards.

What you do is look around the board and add up all the Babies, then cancel those out against all the 10s. It's important to understand that this board count should include your hand as well as the dealer's up-card. If the cards are distributed evenly, there will be the same total of each. But often, they'll be quite lopsided.

With the following three doubling hands, just hit rather than double if the specified minimum number of extra 10s are on board.

Here's how to use the chart. Suppose you have the A/2 against a 5 and the only other three players at the table have K/J, 10/8, and Q/10. Since there are three more 10s than Babies on board, you should no longer double down, but just take a hit.

These are the only three doubling hands a basic strategy player should ever not double with in a shoe game. As for classics like 11 against a 10, or 10 against a 9, or A/7 against a 3 -- don't mess with them, they're not close. Pull the trigger and double them every time -- as well as all other basic strategy doubles.