# Thread: Double Down on Soft 12

1. Did you find this post helpful? Yes | No
Originally Posted by Gronbog
These data were extracted from the sims I ran to generate indices for the upcoming book from Don and I. Too be fair, though, these specific plays are not discussed.
Gronbog and Don, when do you expect your new book to be available? Will there be a kindle version of the book?

2. Did you find this post helpful? Yes | No
Anthony Curtis said before Christmas. We shall see. I'm going to see him next week and will discuss. Don't know about Kindle.

Don

3. Did you find this post helpful? Yes | No
Apparently this thread is talking about two different sets of rules, one of which is clear and the other is not.

1) The OP states that the rules are as follows: 6D,S17,DOA,DAS,SPA1,NS and the decks are shuffled after each hand.
As can be deduced from the photo of the basic strategy, it is possible to DD with soft-12, that is, after splitting a pair of aces and receiving
another ace in one of the hands (or in both).
Under this scenario it is only possible to count cards if there are multiple players at the table. Obviously the bets will be flat.
If the player is not counting cards the basic strategy is the one mentioned by k_c.
Therefore, the basic strategy would be:
6D, S17 (or H17)
AAv6 ==> DD
AAv5 ==> H
AAv4 ==> H
(Even removing three or four aces is still the same)
The expected values can be verified in BJA3.

2) The second set of rules has not been specified. If we assume that there is no shuffling after each hand, counting cards would make more sense in this case.
Gronbog assumes 6D (S17 or H17) and Hi-Lo as the counting system.
The indices are fine, but there is a little detail that was overlooked in their generation. For example:
AAv6 assumes that two aces and a six were removed from the pack and this implies that when you receive that hand you are NOT able to split the pair of aces.
What would have to be done is to remove three aces and a six to make the calculation since the soft-12 appears after splitting the first pair.
What is the difference? Let's see:

a) S17

AAv6 ==> DD if TC >= 0 (two aces and a six removed)
AAv6 ==> DD if TC >= -1 (three aces and a six removed)

b) H17

AAv6 ==> DD if TC >= -1 (two aces and a six removed)
AAv6 ==> DD if TC >= -2 (three aces and a six removed)

Sincerely,
Cac

4. Did you find this post helpful? Yes | No
When resplitting is not allowed, Double A-A vs 6 (if allowed) if:
(s17) number of decks <= 12
(h17) always
otherwise hit

Correct. By example for 6 decks, I got:

s (17)
A, A vs 6

db = 0.190709
hit = 0.187974

h (17)
db = = 0.206312
hit = 0.189536

Here the dealer is somehow penalized for the “greed” of hitting soft seventeen, with the player increasing the expectations of both actions.

When resplitting is not allowed, Double A-A vs 5 (if allowed) if:
(s17) decks <= 2
(h17) decks <= 2
otherwise hit

Agree. Very close but correct.

For 2 decks and s (17):

db =0.170637
hit = 0,169241

hit A-A vs 4 if resplit is not allowed, do not double

Again, for 6 decks and s (17):

db = 0.071156
hit = 0.129004

Here doubling looks but foolish (with BS only).

My two cents.

Zenfighter

5. Did you find this post helpful? Yes | No
S17 games are so rare these days (except PA and high limit), H17 should be used as the default standard.

6. Did you find this post helpful? Yes | No
Originally Posted by 21forme
S17 games are so rare these days (except PA and high limit), H17 should be used as the default standard.
All Europe has S 17

7. Did you find this post helpful? Yes | No
S 17

8. Did you find this post helpful? Yes | No
Originally Posted by Cacarulo
The indices are fine, but there is a little detail that was overlooked in their generation. For example:
AAv6 assumes that two aces and a six were removed from the pack and this implies that when you receive that hand you are NOT able to split the pair of aces.
What would have to be done is to remove three aces and a six to make the calculation since the soft-12 appears after splitting the first pair.
No such detail was overlooked in my generation of these indices. The indices were computed using simulation and therefore the data were collected across a wide variety of naturally occurring hand compositions, remaining deck compositions and penetrations. No attempt was made to construct representative instances of the possible situations.

9. Did you find this post helpful? Yes | No
No attempt was made to construct representative instances of the possible situations.

Let´s try then, with the aid of exact 6dks EoR´s (checksum = -2.46109 e -13) plus combinatorial analysis, I get the following results:

S (17) doubling A, A vs 6

Removing a, a, 6.

Db if TC > - 0.355349

removing a, a, a, 6

Db if TC > - 0.837136

H (17) doubling A, A vs 6

Removing a, a, 6

Db if TC > -1. 32251

removing a, a, a, 6

Db if TC > -1,73297

That every derived index has a certain element of faith in its generation, no matter if it is with Monte Carlo simulated runs, and/ or with the aid of exact combinatorial, is still a valid assumption, that Griffin foresaw, almost now, 43 years ago. Here the discrepancies between your figures and mine, and specially for the h17 ones, speak for themselves. A matter of faith, then? I will agree for close decisions mainly, but not for this case of doubling with the H17 rule in effect. The full -deck favorability for carry on the action, namely, to double down equals:

m (6) = 0,971026

And thus, your h17 index can´t be equal to zero, no matter how naturally it has occurred in your sims. It must be lower, then. Think about it, Gronbog. An “Old-Timer” advice, btw.

Zenfighter

10. Did you find this post helpful? Yes | No
Zen, after reading your post I was dreading the thought of hashing through all the possible reasons why our results might differ. After all, you and your work are respected here by many.

Thankfully that won't be necessary. I also get -1 as the H17 index for doubling A,A vs 6. The 0 that I posted was a sloppy oversight when transcribing my numbers. I copied the S17 numbers first and then edited them for H17. I wanted to edit my original post to reflect this, but the time allowed for editing has expired.

11. Did you find this post helpful? Yes | No
Originally Posted by Gronbog
No such detail was overlooked in my generation of these indices. The indices were computed using simulation and therefore the data were collected across a wide variety of naturally occurring hand compositions, remaining deck compositions and penetrations. No attempt was made to construct representative instances of the possible situations.
Ok, I understand what you are doing. Would you mind checking AAv3 again (S17 and H17)? I got +7 for both cases. We also have a discrepancy in AAv6. For S17 I got -1 and for H17 I got -2.
Maybe it has to do with penetration, I don't know. I am using 4.5/6.

Sincerely,
Cac

12. Did you find this post helpful? Yes | No
I have AAvs3 S 17 (+8.3) H17 (+8.1)

13. Did you find this post helpful? Yes | No
Originally Posted by Gramazeka
I have AAvs3 S 17 (+8.3) H17 (+8.1)
Hi Grama, +8 (S17 or H17) is correct only if splitting in not allowed even once.

Sincerely,
Cac

Page 3 of 6 First 12345 ... Last

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•