Double Down on a 6:5 Blackjack? Read This First…


Bad Choice

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!

6:5 Blackjack sucks. Don’t make it even worse. Do Not Double Down on Blackjack!

About the Author

Creator of, very few can rival Ken's experience and knowledge of blackjack. His blackjack resume includes winning numerous tournament winnings, making several TV appearances and authoring multiple books on blackjack tournament strategy. Discover more about Ken's background and how he got started here

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Palace Station has many 6-5 tables now and the 3:2 tables are sometimes full. So I played their 6:5 game for the first time with the tie side bet (half of main bet, pays 10:1 on push). Unless my math is horrible, one should actually double on blackjack for some dealer up cards (if not all?). So using your math, with a dealer up card of 5, the $50 pay out on a tie 7% of the time would add $3.50 to the $6.82. If you take the 6:5 blackjack you only get $7 because you lose the tie side bet ($12-$5). Then the question becomes, Bet $15 to win $7 or double down to bet $25 to win $10.32 with a 5 up card? How does it work out for the other up cards? The tie side bet actually lowers the house edge on a regular 3:2 game but obviously you don’t double blackjack on 3:2 even with the side bet. But I’m curious if the tie side bet substantially lowers the house edge on a 6:5 game if you double some blackjacks?


I am a dealer on a strip casino and of you have a blackjack or …soft 11….and the dealer has a 5 or 6 showing you ALWAYS DOUBLE DOWN

Sam Tanner

I’ve been playing blackjack for a while and counting for about 5 years. I recently (about a year ago) decided to up my game a bit and learn how and when to deviate from basic strategy as dictated by the count.

I believe it’s Stanford Wong’s book that said that although there are about 50 variations from basic strategy the only 3 of any importance and significance in winning are: (1) taking insurance when the count is +3 or more; (2) stay on 16 vs. dealer 10 when the count is 0 or higher and (3) stay on 15 vs. dealer 10 when the count is +4 or higher.

I’m embarrassed to say that I also just discovered that there are some basic strategy variations depending on whether or not the dealer stays on 17 or hits. A player mentioned that to me and I wasn’t sure if I should believe him or not because I thought that I had researched this before and couldn’t find any difference or even find mention of a difference. I decided to research it again and discovered your website. With the ability to plug in the casino rules (# of decks, hit or stay on soft 17, etc.) on your site I learned that in fact there is a difference.

Then I dove deeper into your sight and started going through your course. This is where I have been devastated. I discovered that my whole method of money management was wrong.

I don’t know where I learned it from but I’m quite sure that I didn’t just make it up. I would multiply my bet by the true count. If I’m playing $25 and the count was +4 I’d bet $100.

Now I see that not only must you increase your bet by .38% of your bankroll but that percentage is based upon your current bankroll (so as you make lose money that bankroll changes and therefore that betting unit changes).

I’m devastated! I worked my butt off to learn basic strategy. I learned to count and think that I’m quite good at it. I have the patience to grind it out at a table and play for hours and days at a time to enhance my odds. But: (1) I don’t think that I’m smart enough to calculate .38% of my bankroll as I’m playing and (2) I don’t have enough money to play based upon those guidelines.

I usually take about $1,000 to play. Based upon that bankroll, unless I’m doing something wrong, the count has to get to +8 until I’m directed to even bet what is typically the minimum ($25) where I play (Maryland Live or Tropicana in AC). Even with a $3,000 bankroll the count has to get to +6 before you can even double your bet. To be able to double your bet when the count is +2 your bankroll has to be around $13,000.

Please guide me:
1. Am I now calculating the betting increment correctly?
2. Am I correct in stating that you need a lot more than $1,000 when counting?
3. Is there not an easier way to calculate the optimum bet?
4. Is my method of multiplying my bet by the true count way off base (I suspect it is)?
5. Is it correct that taking insurance at +3 or more, staying on 16 vs. 10 at 0 or more and staying on 15 vs. 10 at +4 or more are the only variations from basic strategy while counting that make any significant difference in your winning?

Ploppy Mcplopperson

Ken is this bet ramp ok? +1 $10 +2 $50 +3 2X$50=$100 +4 2X$75=$150 +5 or higher im maxing at 2X$100. Played at this particular casino for 2-3 months; been doing well with no pit critter sweat.


Whoa here. I understand that varying one’s bet raises a red flag that you are probably a card counter. How does one camouflage bet variations to avoid being caught?

Jewell Ledwell

I just started blackjack in casinos last week. Thanks for all the tips.

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