Double down on a blackjack?

In every casino I've been to, when someone gets a blackjack, the dealer will pay them their 3/2 payment as soon as it is their turn. Would a casino allow a double down bet on a blackjack (soft 11)? I know it's risking a sure 3/2 win to try for a 2/1 win, with the possibility of losing double the original bet, but could a player benefit if they doubled down on a blackjack when a dealer is showing a 6?

No.

see for example, if doubling after split aces allowed

It's better to STAND and take 1:1 on a 21 then it is to double.

In blackjack tournement play you can double a bj
and sometimes it is essential that you do if you need
to overtake another player's chip count and 1.5x will
not suffice.

In normal play I wouldn't recommend it even for
a 6:5 game.

This is a good time to remind those who play 6:5 to always take even money. Many casinos don't offer it on these games but if they do, grab it.

dwheatley, what are you answering "no" to? Your answer has nothing to do with the question I asked.

So in tournament blackjack it is allowed, but in tournament play you may have to throw the strategy tables out of the window in extreme situations. I could see someone who needs to make up a deficit very fast would bet max and double down on a 12 or 13.

But in standard, casino blackjack, is a double down on a blackjack permissible? I can see it's not recommended, but is it allowed? (Hitting on 20 is allowed but certainly not recommended!)

Quote: canadianbacon

dwheatley, what are you answering "no" to? Your answer has nothing to do with the question I asked.

So in tournament blackjack it is allowed, but in tournament play you may have to throw the strategy tables out of the window in extreme situations. I could see someone who needs to make up a deficit very fast would bet max and double down on a 12 or 13.

But in standard, casino blackjack, is a double down on a blackjack permissible? I can see it's not recommended, but is it allowed? (Hitting on 20 is allowed but certainly not recommended!)

You asked two questions in your initial post:
1. would a casino allow a player to double a soft 11?
2. could a player benefit by doubling a soft 11 against a 6?

The answer to #1 is maybe. Some might, but the vast majority do not allow it. The answer to #2 is no. It isn't beneficial to the player in the course of ordinary casino play.

Quote: canadianbacon

But in standard, casino blackjack, is a double down on a blackjack permissible? I can see it's not recommended, but is it allowed? (Hitting on 20 is allowed but certainly not recommended!)

It is definately not recommended because although your payout would be higher if you doubled down and won, you your profit percentage would be lower in that instance (not to mention your losses if it doesn't pan out).

My guess is that it would very from casino to casino...but if they are smart they will let you do it becasue it is to there advantage for you to "forfit" an automatic winner.

According to the Wizard's appendix 8, 8 decks, dealer stands on S17,

The EV of doubling 10-A on a 6 is .669, much less than the 1.5 on a blackjack. Always take blackjack, even if it's 6-5, or even money for that matter.

The Indiana Gaming Commission forbids doubling down on a blackjack. of course it would be foolish to do so even if allowed in Indiana.

Quote: boymimbo

According to the Wizard's appendix 8, 8 decks, dealer stands on S17,

The EV of doubling 10-A on a 6 is .669, much less than the 1.5 on a blackjack. Always take blackjack, even if it's 6-5, or even money for that matter.

Thanks, that's exactly what I was looking for. I would have thought the disparity would have been less, but there's my answer...