Doubling vs. Ace Up

[Jeff Dubya]

OK, so during my six hours of friday night blackjack I got into quite a discussion with another player and a dealer about doubling vs. an ace.

Now, the tables say that 10 doubles up to 9 and an ace doubles up to 10. However, they both said an ace should double against an ace, and here is why:

If the dealer has an ace up he or she will always check for blackjack.

If the dealer doesn't flip those cards over immediately, you can assume that the most a dealer has is 20. In effect, they say, it's the same as doubling against that ten.

Now I *know* that Renzey and others say to never assume a ten undereath, and that was my argument against doubling A vs. A, additionally, if the dealer has a lower card in the hole, that due to the soft nature of the ace, they could have nearly twice as many opportunities to make a hand as with a 10.

I'd love to hear your thoughts on this.

PS - I have also read that where the rules have the dealer hitting on soft 17 that the basic strategy changes so that A hits vs. A anyhow. Has anyone else seen this?

 

[Canceler]

Okay, I'm confused

When you talk about A vs. A, do you really mean 11 vs. A? If so, yes, double 11 vs. A if the dealer hits soft 17 in multi-deck games.

 

[JJcoolL830]

doubling vs. Ace

The probability of the dealer busting when showing an ace after checking for blackjack is roughly 17%. This is much lower than any other up card the dealer might show.

The reason for such a low percentage is the dual nature of the ace either being a 1 or 11, the dealer simply has much more chances when hitting to make a pat hand. Although the play 11 vs A is a close call, this is why you would not double against an ace in a 6 deck shoe, because if you pulled a 2-5 on your double down... you are pretty much dead in the water.

However, In a single deck it is slightly advantageous to double your 11 versus an ace since the balance of high cards to low ones is slightly skewed in your favor (sorry, its a poor explanation about the single deck game)

 

[Jeff Dubya]

When you talk about A vs. A, do you really mean 11 vs. A?

Dammit, yes. I knew I would screw that up trying to articulate my question.

11 vs. Ace Up. Sorry.

 

[Mikeaber]

If the dealer hits soft 17's, I'll double an 11 against anything, including Aces. If you double that 11 ALL the time, you will come out ahead. But, if you start going by intuition...you'll probably be better off by not doubling. We're talking about playing Basic Strategy without any "advantage" play.

I played 18 hours Friday and Saturday (today) at AmeriStar in Kansas City. I played straight Basic Strategy on a 6-deck table where the dealer hits all soft 17's. After all those hours of play, I was dead even....no exageration...EXACTLY even! The tables at AmeriStar seat 7 players. Very crowded conditions. I wish to heck that they had left the tables with six-spot felt. Had a hoot of a time doing it though because our friends at AmeriStar comp'd the entire stay....food and room.

AmeriStar is the 9th largest casino in the world. Yet, I've played there so much that the Dealers and Pit Bosses know me by name <LOL>. However, it is not my doings at the casino on the BJ tables that earn all the comps! It's my wife who accumulates all the free stuff with her slot play <sigh>.

 

[cyclinggimpe]

I sometimes double my Ace when the dealer has an Ace. Up here in BC, Canada, the dealers don't deal a hole card; so, they don't check if they have a blackjack yet. If we double and they get a BJ, we only lose our initial bet. Same goes with splits and their doubles; only the initial bet gets lost. But if the dealer doesn't get BJ and he beats you, then you lose all bets. I'll only double my Ace if the dealer has been getting a lot of BJ's in my session (and that happens a few times). Others would probably disagree with my play; but, it's not their money I'm playing with.