I was at a blackjack table in a casino ealier today when I hit blackjack. I told the dealer that I wanted to count the ace as a one and double down against his six, but he said he didn’t that I was allowed to do it. He called a manager and the manager said no one has ever asked to do such a thing. My two questions are:am I allowed to do it and would it be worth it since I already win 1.5 percent with the blackjack alone?
On the wikipedia entry about Blackjack, it says “An ace’s value is 11 unless this would cause the player to bust, in which case it is worth 1.”
If that’s true, then you can’t do the thing you were asking to do.
-FrL-
It’s an interesting thought, but in my limited knowledge about the game, I’ve always heard that a blackjack is an instant win; no options available.
You doin’t seem to know much about blackjack. I don’t meen to seem overly hostile, but your answer seems to be the stupidest thing I have ever read on the straight dope. If I have a king, calling it eleven would not cause me to bust, but this is like saying that a king is a face card. Duh!!!
Yeah, since you have a king and therefore won’t bust, the ace counts as 11. His post makes perfect sense. And I’m pretty sure trying to double down in that situation is not a good idea.
Everywhere I have played black jack they would payout immediately upon dealing black jack.
Most casinos pay black jack at 150% of your bet. Doubling down instead of taking your winnings seems like a pretty poor strategy unless you know that almost all of the cards left will cause the dealer to bust.
Wow. I’m left speechless after reading that.
You don’t seem to know much about the Straight Dope, if you think that’s the stupidest thing you’ve read here. Give it time.
Now then, re-read what he said. An ace’s value is 11 unless this would cause the player to bust. Which means when paired with a 10, you have 21, which is not a bust, which means the value of the Ace must be 11.
Your sentence “If I have a king, calling it eleven would not cause me to bust” is inaccurate because you’re treating the Ace as a 1 even before you verify whether or not you’d otherwise bust (hint: you won’t).
OK - here’s my take:
Let’s say you bet 10 dollars. As the hand stands (you have blackjack), you will win 15 bucks.
If you are allowed to double down, you can add another 10 and potentially win 20 bucks. That means that you are risking 15 bucks to win an additional 5. That logic right there is enough to stop me from doubling down, but let’s press on.
We’re going to have to simplify what happens next, since there’s no telling what card you will get, what the dealer’s hole card is, or what the dealer will draw. Sure, math could help us out - but hell, I’ll be the first to admit, I can’t do the complex math that’s required in this situation.
According to this site, the dealer’s bust percentage showing a 6 is 42%. In this situation, you are basically looking for the dealer to eat a 10 and bust. So there’s a 58% chance he won’t. If you assume that if the dealer doesn’t bust then you will lose, then it’s not a good bet — then it doesn’t make sense.
Granted you could still win, depending on the cards — but it doesn’t make sense to me to push away guaranteed money in return for what amounts to 1/2 of your original bet.
Also re: the kerfluffle with DoWahDiddy — copperwindow’s point is that even though the Ace is counted as an 11 when it’s paired with the King - IF THE PLAYER HAS THE OPTION TO DOUBLE DOWN - then when he gets the next card, it will count as a one (because otherwise the player would have busted). The wikipedia link is simply unhelpful with regard to whether a player COULD double down on a “soft 21.”
Of course the “value of the Ace must be 11” when the cards are dealt. But that is totally irrelevant to whether you can hit/double down on a blackjack.
Also copperwindow — probably a nicer way to handle that.
Ah crap, forgot to add this — this is how I’ve always understood it too, DooWahDiddy.
But to be honest, I’ve never politely asked to double-down on a Blackjack. Call me crazy! 
If I read this right, the House should have let you double down on your blackjack vs. the dealer’s six. Your return on a $1 bet with a blackjack is an automatic $1.5, but this table seems to say that doubling down on an A-10 would result in a payoff of 0.66 and change. If you were to double down in that situation a number of times, your expected payoff would be less than half of what you’d otherwise get claimiing your blackjack. So, setting aside the question of whether you can do it, it seems that it is not advisable to.
Ah, right you are. copperwindow, I do see your point (and I did say it was an interesting thought) but I still think it’s not allowed, or even smart, from an “odds-only” point of view.
And I second Doctor Who’s comment about taking it easy in GQ, especially since Frylock was just quoting something from another source (i.e. Wikipedia).
If the rule from Wikipedia is in fact a rule of blackjack officially, then you are wrong, or at least, you are misunderstanding something.
Here’s the relevant rule from the wiki:
“It’s an 11 unless this would cause you to bust, then it’s a one.”
Now, your cards were, say, an ace and a king.
What is the value of that ace, according to the quoted rule? The value of the ace, according to the quoted rule, is 11. This is because it’s being 11 does not cause your hand to bust.
And that, according to the rule, is the end of the inquiry. There’s no question of whether the value can be one or not–that question is answered by the conclusion already reached: It’s value is 11.
As the Wikipedia article reads, there is no situation in which you get to choose the value of the ace. The value is determined by the situation, by the rule I just quoted.
That’s what the wiki says, anyway, and that’s the correct way to apply the rule found in that wiki. Inasmuch as you thought the correct application of the rule found in the wiki is other than what I’ve said, your issue is indeed with me. Inasmuch as you think the rule found at the wiki is not a valid rule of blackjack, then your issue is with the wiki article, not with me.
-FrL-
Frylock —
Let’s say copperwindow was dealt an Ace and a King. He has 21. He has blackjack. The King is worth 10, and, according to your rule, the Ace is automatically worth 11.
The problem is that noone is arguing that. We all agree that the Ace (as it is dealt) is worth 11.
The real question in the OP is: Can you hit on that Ace/King blackjack combination? (Doubledown in the OP but it’s the same concept). Because hitting on that “soft 21” will not cause you to bust. It will however reduce the value of the ace to 1.
In my gut - I feel like the casinos will let you hit on that 21 if you want. Why? Because (a) it’s taking a guaranteed payout of 1.5x your bet and putting it back into play - thus giving the casino an opportunity not to lose (and the only risk to the casino is losing another .5x your bet). And (b) because unless you get a dealt a 10/face card — you have drawn a worse hand. And then the dealer has a chance to beat you. That’s my gut feeling, but I don’t know the answer.
Again Frylock — your rule is entirely correct, but it’s just not really pertinent to the OP.
Ah. Frylock, I apologize if I’m misunderstanding your posts, but in re-reading them - I think this is where the confusion lies.
As you state, it’s true that the situation dictates the value of the Ace. So Ace/King is dealt. Ace is worth 11. Easy, right? Then you hit and get a 3. Now the Ace is worth 1. The value of the ace is totally contingent on the situation.
But that’s not the issue. The real issue is NOT whether you can “choose” the value of the ace. The question is whether you can hit/doubledown on a “Soft 21” (which is a guaranteed win).
Now — you may be arguing that the hand is automatically over when you get the Ace/King because (a) the Ace is worth 11 according to the rule, and (b) you have 21 which means the hand is over. If so, we will need a rule that says that a player cannot hit on 21 - even if it’s soft. And one has not been offered up yet.
But here’s the relevant sentence from the OP:
That means I’m right, right? 
-FrL-
So did the manager allow it or not? I mean, I know he said it’s never been allowed, but did he allow it? Because in Atlantic City they automatically pay out when you get an ace and a facecard, not even giving you time to say that you want to make it a 1 or 11.
Say you have this rule:
A: When you have a 21, the hand is over.
Couple this with
B: An ace counts as 11, unless this would cause the hand to bust, in which case the ace counts as 1.
These two rules, taken together, do lead to the conclusion that you can not hit on a soft 21.
The ace, as has been established, counts as 11 because this doesn’t cause a bust. So the total for the hand is 21. So rule A indicates the hand is over.
So we don’t need a rule that says anything explicit about soft 21s, we just need a rule that says what A says. Is there such a rule?
-FrL-
To respond to my own question after some wiki reading:
From the wiki article, we have
And
I interpret these uses of the word “automatic” to preclude any optional continuation of the hand, but I recognize that it’s not absolutely clear on this point.
The wiki article’s all I’ve looked at. Is there something more official that can be consulted?
-FrL-
A quick survey of online rules uniformly says the player automatically wins with a blackjack, and one cites rules casinos have against allowing a double-down if the payer has been dealt an ace. The Montreal Casino specifically forbids doubling down if you have 21 on your first two cards. I gather, then, that if you plan to employ this strategy, it’s in your interest to ask in advance.
Further research shows that when the dealer has an up 6 and the player has 11, the player has a 67% edge (assuming I’m reading this right; 2 to 3 at best). I figure your expected payout after doubling down is [.662 + .33(-1)] = 1, while just taking the blackjack guarantees you a 1.5. Why would you use this strategy even if it was available?