david: Double down on a 9

[david]

I'm a blackjack newbie and I'm learning the basic strategy with the aid of a simulator I've written which you can see at
http://home.earthlink.net/~davidwchan/BJApplet.htm

The question I have is that my simulator seems to imply that I should double down when I have a 9 and dealer is showing a 2 or 7 whereas everyone seems to say you should hit. Is there some other research out there I can look at to see what others come up with?

The result I come up with is that for a dealer showing 7, I will win 48% and lose 43% of the time. For a 2, it's win 48% lose 44%.

David

[Don Schlesinger]

> The question I have is that my simulator
> seems to imply that I should double down
> when I have a 9 and dealer is showing a 2 or
> 7 whereas everyone seems to say you should
> hit.

What game are you playing -- with specific rules?

It is certainly correct, under some conditions, to double 9 vs. 2 (SD, DD). But, it is never BS to double vs. 7.

Don

[David]

> What game are you playing -- with specific
> rules?

> It is certainly correct, under some
> conditions, to double 9 vs. 2 (SD, DD). But,
> it is never BS to double vs. 7.

> Don

Tried it on sd, dd and 6d. s17. What are the percentages on double vs 7?

David

[Jake {|:>)]

If you are smart enough to write and use a simulator before hitting a casino I would think that you would get a lot of value out of buying Peter Griffin's Theory of Blackjack. Before you hit the casinos I think you should go out and buy Don's excellent book, Blackjack Attack.

There are many close play options and some not so close where hitting and doubling both yield a profit. The question is which makes more ? Even that horrible play of splitting tens against a six for example will yield a profit. However it is considerably less than standing on a cold twenty.

Good luck to you.

Jake Smallwood

[Rusty Starfish]

Just curious, because it looks like your figures are definitely off. I was wondering if you forgot to take into account that you'd only receive one card on a double down. If the figures you posted are wins-losses based on hitting more than once (in keeping with BS, you'd hit until you had seventeen or more), then the figures you gave wouldn't be entirely relevant.
This error would be hard to notice when you're also looking at the doubling results for 10v7 and 11v7. You may have made the same error with them, but it wouldn't be as obvious, since the results you got there might still concur with BS.