Double down on Blackjack

The plague of 6:5 blackjack has been well documented here. (See 6 to 5 Blackjack? Just say No! and The Casino Floor as a Minefield.)

If you have any other game choices available, you should not be playing a game that pays only 6:5 on blackjack.

Yet some players do play these games. Don’t worry, I’m not going to chastise you if you sometimes play these games. But I do want to make sure that you are not making a bad game even worse…

How to Give Away Money

Several players have told me that when they are playing a 6:5 game and are dealt a blackjack, they choose to double down on the blackjack as an eleven instead. Ack! No. No. No. Let me explain just how bad an idea this is.

Let’s say you are a $10 player, and are dealt a blackjack at a 6:5 game. Assuming that the dealer doesn’t also have a blackjack, you’ll win $12 on the hand. Guaranteed, with no chance of losing money. This hand is worth $12. Period.

If you decide to double down on the blackjack instead, you’re risking another bet with the hope of winning $20 instead of $12. But you’re giving up the guarantee of a win. Let’s see how that works:

A Bird in the Hand

Let’s take the best possible scenario, a single deck game where the dealer stands on all 17s. We are dealt a blackjack against a dealer upcard of 5. If we let the dealer pay the blackjack, we collect our 6:5 guaranteed win of $12. That’s our “bird in the hand”. For doubling to be a better strategy, our yield on the double down needs to average more than $12. And it’s not even close. Let’s look at what happens when we double.

Two in the Bush

Now we are doubling our bet to $20 and drawing one more card. Remember, I chose the best possible hand for this… (Ace, Ten) vs a dealer 5.

This is a very strong double down hand, but even so, it will win only 63% of the time. 7% of the time we will push, and 30% of the time we will lose. (Here’s how to calculate the value if you are interested: (63% – 30%) X $20 = $6.60. Actually, I rounded off the percentages a bit so the exact answer is slightly different…)

The value of this doubled bet of $20 works out to just $6.82. That’s only a little over HALF the value of the 6:5 blackjack.

In this case, A Bird in the Hand is definitely worth more than Two in the Bush. Every time a $10 bettor chooses to double down on his blackjack, he’s giving the casino an extra five bucks and change. Don’t do it!

• Double In Blackjack
• Doubling down in Blackjack
• Double Exposure Blackjack